A fragment of the detailed backtrace:

#0  0xb6f154b8 in sigc::internal::signal_impl::notify(void*) () from /usr/lib/i386-linux-gnu/libsigc-2.0.so.0
#1  0xb6f15f22 in sigc::internal::slot_rep::disconnect() () from /usr/lib/i386-linux-gnu/libsigc-2.0.so.0
#2  0xb6f16151 in sigc::slot_base::disconnect() () from /usr/lib/i386-linux-gnu/libsigc-2.0.so.0
#3  0xb6f15e11 in sigc::connection::disconnect() () from /usr/lib/i386-linux-gnu/libsigc-2.0.so.0
#4  0x08207d6e in sp_style_clear (style=0xd2c7f08) at style.cpp:3044
#5  0x0820ba5f in sp_style_read (style=0xd2c7f08, object=0xd2c7da8, repr=0xa3037f0) at style.cpp:647
#6  0x081ddf4f in SPObject::set (this=0xd2c7da8, key=9, value=0x0) at sp-object.cpp:902
#7  0x081b3601 in SPItem::set (this=0xd2c7da8, key=9, value=0x0) at sp-item.cpp:509
#8  0x081ff0e8 in SPUse::set (this=0xd2c7da8, key=9, value=0x0) at sp-use.cpp:155
#9  0x081dbaef in setKeyValue (value=<optimized out>, key=9, this=0xd2c7da8) at sp-object.cpp:915
#10 SPObject::readAttr (this=0xd2c7da8, key=0x892e2ac "style") at sp-object.cpp:932
#11 0x081b17eb in SPItem::build (this=0xd2c7da8, document=0x8f01e40, repr=0xa3037f0) at sp-item.cpp:389
#12 0x081ff3a0 in SPUse::build (this=0xd2c7da8, document=0x8f01e40, repr=0xa3037f0) at sp-use.cpp:76
#13 0x081db753 in SPObject::invoke_build (this=0xd2c7da8, document=0x8f01e40, repr=0xa3037f0, cloned=1) at sp-object.cpp:722
#14 0x081ffd38 in SPUse::href_changed (this=0xd2c7720) at sp-use.cpp:436
#15 0x0821d931 in emit (_A_a2=<optimized out>, _A_a1=<optimized out>, impl=<optimized out>)
    at /usr/include/sigc++-2.0/sigc++/signal.h:1252
#16 emit (_A_a2=<optimized out>, _A_a1=<optimized out>, this=<optimized out>)
    at /usr/include/sigc++-2.0/sigc++/signal.h:2891
#17 Inkscape::URIReference::_setObject (this=0xd2c7b58, obj=0xd2c7c18) at uri-references.cpp:124
#18 0x0821dd41 in Inkscape::URIReference::attach (this=0xd2c7b58, uri=...) at uri-references.cpp:94
#19 0x081ff208 in SPUse::set (this=0xd2c7720, key=13, value=0xa2bd450 "#b") at sp-use.cpp:142
#20 0x081dbaef in setKeyValue (value=<optimized out>, key=13, this=0xd2c7720) at sp-object.cpp:915
#21 SPObject::readAttr (this=0xd2c7720, key=0x882f82b "xlink:href") at sp-object.cpp:932
#22 0x081db753 in SPObject::invoke_build (this=this@entry=0xd2c7720, document=document@entry=0x8f01e40, 
    repr=repr@entry=0xa303670, cloned=1) at sp-object.cpp:722
#23 0x081de121 in SPObject::build (this=0xd2c71a0, document=0x8f01e40, repr=0xa3036f0) at sp-object.cpp:655
#24 0x081db753 in SPObject::invoke_build (this=0xd2c71a0, document=0x8f01e40, repr=0xa3036f0, cloned=1) at sp-object.cpp:722
#25 0x081ffd38 in SPUse::href_changed (this=0xd2c6aa8) at sp-use.cpp:436
#26 0x0821d931 in emit (_A_a2=<optimized out>, _A_a1=<optimized out>, impl=<optimized out>)
    at /usr/include/sigc++-2.0/sigc++/signal.h:1252
#27 emit (_A_a2=<optimized out>, _A_a1=<optimized out>, this=<optimized out>)
    at /usr/include/sigc++-2.0/sigc++/signal.h:2891
#28 Inkscape::URIReference::_setObject (this=0xd2a68a0, obj=0xd2c7028) at uri-references.cpp:124
#29 0x0821dd41 in Inkscape::URIReference::attach (this=0xd2a68a0, uri=...) at uri-references.cpp:94
#30 0x081ff208 in SPUse::set (this=0xd2c6aa8, key=13, value=0xa2bd478 "#c") at sp-use.cpp:142
#31 0x081dbaef in setKeyValue (value=<optimized out>, key=13, this=0xd2c6aa8) at sp-object.cpp:915
#32 SPObject::readAttr (this=0xd2c6aa8, key=0x882f82b "xlink:href") at sp-object.cpp:932
#33 0x081db753 in SPObject::invoke_build (this=0xd2c6aa8, document=0x8f01e40, repr=0xa3037f0, cloned=1) at sp-object.cpp:722
#34 0x081ffd38 in SPUse::href_changed (this=0xd2c6420) at sp-use.cpp:436
#35 0x0821d931 in emit (_A_a2=<optimized out>, _A_a1=<optimized out>, impl=<optimized out>)
    at /usr/include/sigc++-2.0/sigc++/signal.h:1252
#36 emit (_A_a2=<optimized out>, _A_a1=<optimized out>, this=<optimized out>)
    at /usr/include/sigc++-2.0/sigc++/signal.h:2891
#37 Inkscape::URIReference::_setObject (this=0xd2c6858, obj=0xd2c6918) at uri-references.cpp:124
#38 0x0821dd41 in Inkscape::URIReference::attach (this=0xd2c6858, uri=...) at uri-references.cpp:94
#39 0x081ff208 in SPUse::set (this=0xd2c6420, key=13, value=0xa2bd450 "#b") at sp-use.cpp:142
---Type <return> to continue, or q <return> to quit---
#40 0x081dbaef in setKeyValue (value=<optimized out>, key=13, this=0xd2c6420) at sp-object.cpp:915
#41 SPObject::readAttr (this=0xd2c6420, key=0x882f82b "xlink:href") at sp-object.cpp:932
#42 0x081db753 in SPObject::invoke_build (this=this@entry=0xd2c6420, document=document@entry=0x8f01e40, 
    repr=repr@entry=0xa303670, cloned=1) at sp-object.cpp:722
#43 0x081de121 in SPObject::build (this=0xd2c5ea0, document=0x8f01e40, repr=0xa3036f0) at sp-object.cpp:655
#44 0x081db753 in SPObject::invoke_build (this=0xd2c5ea0, document=0x8f01e40, repr=0xa3036f0, cloned=1) at sp-object.cpp:722
#45 0x081ffd38 in SPUse::href_changed (this=0xd2c57b0) at sp-use.cpp:436
#46 0x0821d931 in emit (_A_a2=<optimized out>, _A_a1=<optimized out>, impl=<optimized out>)
    at /usr/include/sigc++-2.0/sigc++/signal.h:1252
#47 emit (_A_a2=<optimized out>, _A_a1=<optimized out>, this=<optimized out>)
    at /usr/include/sigc++-2.0/sigc++/signal.h:2891
#48 Inkscape::URIReference::_setObject (this=0xd2c5c68, obj=0xd2c5d28) at uri-references.cpp:124
#49 0x0821dd41 in Inkscape::URIReference::attach (this=0xd2c5c68, uri=...) at uri-references.cpp:94
#50 0x081ff208 in SPUse::set (this=0xd2c57b0, key=13, value=0xa2bd478 "#c") at sp-use.cpp:142
#51 0x081dbaef in setKeyValue (value=<optimized out>, key=13, this=0xd2c57b0) at sp-object.cpp:915
#52 SPObject::readAttr (this=0xd2c57b0, key=0x882f82b "xlink:href") at sp-object.cpp:932
#53 0x081db753 in SPObject::invoke_build (this=0xd2c57b0, document=0x8f01e40, repr=0xa3037f0, cloned=1) at sp-object.cpp:722
#54 0x081ffd38 in SPUse::href_changed (this=0xd2c5128) at sp-use.cpp:436
#55 0x0821d931 in emit (_A_a2=<optimized out>, _A_a1=<optimized out>, impl=<optimized out>)
    at /usr/include/sigc++-2.0/sigc++/signal.h:1252
#56 emit (_A_a2=<optimized out>, _A_a1=<optimized out>, this=<optimized out>)
    at /usr/include/sigc++-2.0/sigc++/signal.h:2891
#57 Inkscape::URIReference::_setObject (this=0xd2c5560, obj=0xd2c5620) at uri-references.cpp:124
#58 0x0821dd41 in Inkscape::URIReference::attach (this=0xd2c5560, uri=...) at uri-references.cpp:94
#59 0x081ff208 in SPUse::set (this=0xd2c5128, key=13, value=0xa2bd450 "#b") at sp-use.cpp:142
#60 0x081dbaef in setKeyValue (value=<optimized out>, key=13, this=0xd2c5128) at sp-object.cpp:915
#61 SPObject::readAttr (this=0xd2c5128, key=0x882f82b "xlink:href") at sp-object.cpp:932
#62 0x081db753 in SPObject::invoke_build (this=this@entry=0xd2c5128, document=document@entry=0x8f01e40, 
    repr=repr@entry=0xa303670, cloned=1) at sp-object.cpp:722
#63 0x081de121 in SPObject::build (this=0xd2c4ba8, document=0x8f01e40, repr=0xa3036f0) at sp-object.cpp:655
#64 0x081db753 in SPObject::invoke_build (this=0xd2c4ba8, document=0x8f01e40, repr=0xa3036f0, cloned=1) at sp-object.cpp:722
#65 0x081ffd38 in SPUse::href_changed (this=0xd2c44b8) at sp-use.cpp:436
#66 0x0821d931 in emit (_A_a2=<optimized out>, _A_a1=<optimized out>, impl=<optimized out>)
    at /usr/include/sigc++-2.0/sigc++/signal.h:1252
#67 emit (_A_a2=<optimized out>, _A_a1=<optimized out>, this=<optimized out>)
    at /usr/include/sigc++-2.0/sigc++/signal.h:2891
#68 Inkscape::URIReference::_setObject (this=0xd2c4970, obj=0xd2c4a30) at uri-references.cpp:124
#69 0x0821dd41 in Inkscape::URIReference::attach (this=0xd2c4970, uri=...) at uri-references.cpp:94
#70 0x081ff208 in SPUse::set (this=0xd2c44b8, key=13, value=0xa2bd478 "#c") at sp-use.cpp:142
#71 0x081dbaef in setKeyValue (value=<optimized out>, key=13, this=0xd2c44b8) at sp-object.cpp:915
#72 SPObject::readAttr (this=0xd2c44b8, key=0x882f82b "xlink:href") at sp-object.cpp:932
#73 0x081db753 in SPObject::invoke_build (this=0xd2c44b8, document=0x8f01e40, repr=0xa3037f0, cloned=1) at sp-object.cpp:722
#74 0x081ffd38 in SPUse::href_changed (this=0xd2c3e30) at sp-use.cpp:436
#75 0x0821d931 in emit (_A_a2=<optimized out>, _A_a1=<optimized out>, impl=<optimized out>)
    at /usr/include/sigc++-2.0/sigc++/signal.h:1252
#76 emit (_A_a2=<optimized out>, _A_a1=<optimized out>, this=<optimized out>)
    at /usr/include/sigc++-2.0/sigc++/signal.h:2891
---Type <return> to continue, or q <return> to quit---
#77 Inkscape::URIReference::_setObject (this=0xd2c4268, obj=0xd2c4328) at uri-references.cpp:124
#78 0x0821dd41 in Inkscape::URIReference::attach (this=0xd2c4268, uri=...) at uri-references.cpp:94
#79 0x081ff208 in SPUse::set (this=0xd2c3e30, key=13, value=0xa2bd450 "#b") at sp-use.cpp:142
#80 0x081dbaef in setKeyValue (value=<optimized out>, key=13, this=0xd2c3e30) at sp-object.cpp:915
#81 SPObject::readAttr (this=0xd2c3e30, key=0x882f82b "xlink:href") at sp-object.cpp:932
#82 0x081db753 in SPObject::invoke_build (this=this@entry=0xd2c3e30, document=document@entry=0x8f01e40, 
    repr=repr@entry=0xa303670, cloned=1) at sp-object.cpp:722
#83 0x081de121 in SPObject::build (this=0xd2c38b0, document=0x8f01e40, repr=0xa3036f0) at sp-object.cpp:655
#84 0x081db753 in SPObject::invoke_build (this=0xd2c38b0, document=0x8f01e40, repr=0xa3036f0, cloned=1) at sp-object.cpp:722
#85 0x081ffd38 in SPUse::href_changed (this=0xd2c31c0) at sp-use.cpp:436
#86 0x0821d931 in emit (_A_a2=<optimized out>, _A_a1=<optimized out>, impl=<optimized out>)
    at /usr/include/sigc++-2.0/sigc++/signal.h:1252
#87 emit (_A_a2=<optimized out>, _A_a1=<optimized out>, this=<optimized out>)
    at /usr/include/sigc++-2.0/sigc++/signal.h:2891
#88 Inkscape::URIReference::_setObject (this=0xd2c3678, obj=0xd2c3738) at uri-references.cpp:124
#89 0x0821dd41 in Inkscape::URIReference::attach (this=0xd2c3678, uri=...) at uri-references.cpp:94
#90 0x081ff208 in SPUse::set (this=0xd2c31c0, key=13, value=0xa2bd478 "#c") at sp-use.cpp:142
#91 0x081dbaef in setKeyValue (value=<optimized out>, key=13, this=0xd2c31c0) at sp-object.cpp:915
#92 SPObject::readAttr (this=0xd2c31c0, key=0x882f82b "xlink:href") at sp-object.cpp:932
#93 0x081db753 in SPObject::invoke_build (this=0xd2c31c0, document=0x8f01e40, repr=0xa3037f0, cloned=1) at sp-object.cpp:722
#94 0x081ffd38 in SPUse::href_changed (this=0xd2c2b38) at sp-use.cpp:436
#95 0x0821d931 in emit (_A_a2=<optimized out>, _A_a1=<optimized out>, impl=<optimized out>)
    at /usr/include/sigc++-2.0/sigc++/signal.h:1252
#96 emit (_A_a2=<optimized out>, _A_a1=<optimized out>, this=<optimized out>)
    at /usr/include/sigc++-2.0/sigc++/signal.h:2891
#97 Inkscape::URIReference::_setObject (this=0xd2c2f70, obj=0xd2c3030) at uri-references.cpp:124
#98 0x0821dd41 in Inkscape::URIReference::attach (this=0xd2c2f70, uri=...) at uri-references.cpp:94
#99 0x081ff208 in SPUse::set (this=0xd2c2b38, key=13, value=0xa2bd450 "#b") at sp-use.cpp:142
#100 0x081dbaef in setKeyValue (value=<optimized out>, key=13, this=0xd2c2b38) at sp-object.cpp:915
#101 SPObject::readAttr (this=0xd2c2b38, key=0x882f82b "xlink:href") at sp-object.cpp:932
#102 0x081db753 in SPObject::invoke_build (this=this@entry=0xd2c2b38, document=document@entry=0x8f01e40, 
    repr=repr@entry=0xa303670, cloned=1) at sp-object.cpp:722
#103 0x081de121 in SPObject::build (this=0xd2c25b8, document=0x8f01e40, repr=0xa3036f0) at sp-object.cpp:655
#104 0x081db753 in SPObject::invoke_build (this=0xd2c25b8, document=0x8f01e40, repr=0xa3036f0, cloned=1)
    at sp-object.cpp:722
#105 0x081ffd38 in SPUse::href_changed (this=0xd2c1ec8) at sp-use.cpp:436
#106 0x0821d931 in emit (_A_a2=<optimized out>, _A_a1=<optimized out>, impl=<optimized out>)
    at /usr/include/sigc++-2.0/sigc++/signal.h:1252
#107 emit (_A_a2=<optimized out>, _A_a1=<optimized out>, this=<optimized out>)
    at /usr/include/sigc++-2.0/sigc++/signal.h:2891
#108 Inkscape::URIReference::_setObject (this=0xd2c2380, obj=0xd2c2440) at uri-references.cpp:124
#109 0x0821dd41 in Inkscape::URIReference::attach (this=0xd2c2380, uri=...) at uri-references.cpp:94
#110 0x081ff208 in SPUse::set (this=0xd2c1ec8, key=13, value=0xa2bd478 "#c") at sp-use.cpp:142
#111 0x081dbaef in setKeyValue (value=<optimized out>, key=13, this=0xd2c1ec8) at sp-object.cpp:915
#112 SPObject::readAttr (this=0xd2c1ec8, key=0x882f82b "xlink:href") at sp-object.cpp:932
#113 0x081db753 in SPObject::invoke_build (this=0xd2c1ec8, document=0x8f01e40, repr=0xa3037f0, cloned=1)
    at sp-object.cpp:722