Reopening as it still happens post 2.4 and causes crashes. This backtrace is an example of many:

Thread 1 (Thread 0x7ffff7e76780 (LWP 2867)):
#0  QTJSC::Identifier::remove (r=0x7fffb9d577e0) at
../3rdparty/javascriptcore/JavaScriptCore/runtime/Identifier.cpp:239
#1  0x00007ffff11e3285 in QTJSC::UStringImpl::~UStringImpl
(this=0x7fffb9d577e0, __in_chrg=<value optimized out>) at
../3rdparty/javascriptcore/JavaScriptCore/runtime/UStringImpl.cpp:68
#2  0x00007ffff11ddb74 in deref (this=0x7fffb9d622c0, __in_chrg=<value
optimized out>) at
../3rdparty/javascriptcore/JavaScriptCore/runtime/UStringImpl.h:168
#3  ~RefPtr (this=0x7fffb9d622c0, __in_chrg=<value optimized out>) at
../3rdparty/javascriptcore/JavaScriptCore/wtf/RefPtr.h:59
#4  QTJSC::Structure::~Structure (this=0x7fffb9d622c0,
__in_chrg=<value optimized out>) at
../3rdparty/javascriptcore/JavaScriptCore/runtime/Structure.cpp:194
#5  0x00007ffff1263530 in deref (this=0x7fffb9755780, __in_chrg=<value
optimized out>) at
../3rdparty/javascriptcore/JavaScriptCore/wtf/RefCounted.h:109
#6  ~JSObject (this=0x7fffb9755780, __in_chrg=<value optimized out>)
at ../3rdparty/javascriptcore/JavaScriptCore/runtime/JSObject.h:303
#7  ~JSVariableObject (this=0x7fffb9755780, __in_chrg=<value optimized
out>) at ../3rdparty/javascriptcore/JavaScriptCore/runtime/JSVariableObject.h:43
#8  QScript::QScriptActivationObject::~QScriptActivationObject
(this=0x7fffb9755780, __in_chrg=<value optimized out>) at
bridge/qscriptactivationobject.cpp:57
#9  0x00007ffff11600e0 in QTJSC::Heap::allocate (this=0x7fffbc747218,
s=<value optimized out>) at
../3rdparty/javascriptcore/JavaScriptCore/runtime/Collector.cpp:419
#10 0x00007ffff1246946 in operator new (this=0x7fffffff9ba0,
engine=<value optimized out>, val=<value optimized out>) at
../3rdparty/javascriptcore/JavaScriptCore/runtime/JSCell.h:162
#11 jsString (this=0x7fffffff9ba0, engine=<value optimized out>,
val=<value optimized out>) at
../3rdparty/javascriptcore/JavaScriptCore/runtime/JSString.h:445
#12 jsString (this=0x7fffffff9ba0, engine=<value optimized out>,
val=<value optimized out>) at
../3rdparty/javascriptcore/JavaScriptCore/runtime/JSString.h:484
#13 QScriptValue::QScriptValue (this=0x7fffffff9ba0, engine=<value
optimized out>, val=<value optimized out>) at api/qscriptvalue.cpp:309
#14 0x00007ffff722ac05 in AmarokDownloadHelper::resultString
(this=0xcee980, url=..., data=..., e=...) at
/home/mark/kde/src/amarok/src/scriptengine/AmarokNetworkScript.cpp:236
#15 0x00007ffff722b120 in AmarokDownloadHelper::qt_metacall
(this=0xcee980, _c=QMetaObject::InvokeMetaMethod, _id=0,
_a=0x7fffffff9dd0) at
/home/mark/kde/build/amarok/src/AmarokNetworkScript.moc:175
#16 0x00007ffff5454bf9 in QMetaMethod::invoke (this=0x7fffffffa1b0,
object=0xcee980, connectionType=<value optimized out>,
returnValue=..., val0=..., val1=..., val2=..., val3=..., val4=...,
val5=..., val6=..., val7=..., val8=...,
   val9=...) at kernel/qmetaobject.cpp:1575
#17 0x00007ffff718d0dd in QMetaMethod::invoke (this=0x7fffffffa1b0,
object=0xcee980, connectionType=Qt::AutoConnection, val0=...,
val1=..., val2=..., val3=..., val4=..., val5=..., val6=..., val7=...,
val8=..., val9=...)
   at /usr/include/qt4/QtCore/qmetaobject.h:119
#18 0x00007ffff718d74a in
NetworkAccessManagerProxy::NetworkAccessManagerProxyPrivate::_replyFinished
(this=0x12010a0) at
/home/mark/kde/src/amarok/src/network/NetworkAccessManagerProxy.cpp:98
#19 0x00007ffff718ce98 in NetworkAccessManagerProxy::qt_metacall
(this=0x12005b0, _c=QMetaObject::InvokeMetaMethod, _id=3,
_a=0x7fffffffa440) at
/home/mark/kde/build/amarok/src/NetworkAccessManagerProxy.moc:86
#20 0x00007ffff5463b27 in QMetaObject::activate (sender=0x22619f0,
m=<value optimized out>, local_signal_index=<value optimized out>,
argv=0x7ffff0af82a0) at kernel/qobject.cpp:3280
#21 0x00007ffff2e88c6b in KDEPrivate::AccessManagerReply::slotResult
(this=0x22619f0, kJob=<value optimized out>) at
../../kio/kio/accessmanagerreply_p.cpp:259
#22 0x00007ffff2e89503 in KDEPrivate::AccessManagerReply::qt_metacall
(this=0x22619f0, _c=QMetaObject::InvokeMetaMethod, _id=<value
optimized out>, _a=0x7fffffffa920) at ./accessmanagerreply_p.moc:83
#23 0x00007ffff5463b27 in QMetaObject::activate (sender=0x12c8630,
m=<value optimized out>, local_signal_index=<value optimized out>,
argv=0x7ffff0af82a0) at kernel/qobject.cpp:3280
#24 0x00007ffff58b9a52 in KJob::result (this=0x0, _t1=0x12c8630) at
./kjob.moc:194
#25 0x00007ffff58b9cf0 in KJob::emitResult (this=0x12c8630) at
../../kdecore/jobs/kjob.cpp:312
#26 0x00007ffff2ec59f3 in KIO::SimpleJob::slotFinished
(this=0x12c8630) at ../../kio/kio/job.cpp:525
#27 0x00007ffff2ec6302 in KIO::TransferJob::slotFinished
(this=0x12c8630) at ../../kio/kio/job.cpp:1118
#28 0x00007ffff2ec3de1 in KIO::TransferJob::qt_metacall
(this=0x12c8630, _c=QMetaObject::InvokeMetaMethod, _id=<value
optimized out>, _a=0x7fffffffad60) at ./jobclasses.moc:367
#29 0x00007ffff5463b27 in QMetaObject::activate (sender=0x22c07d0,
m=<value optimized out>, local_signal_index=<value optimized out>,
argv=0x7ffff0af82a0) at kernel/qobject.cpp:3280
---Type <return> to continue, or q <return> to quit---
#30 0x00007ffff2f7780e in KIO::SlaveInterface::dispatch
(this=0x22c07d0, _cmd=104, rawdata=...) at
../../kio/kio/slaveinterface.cpp:173
#31 0x00007ffff2f74853 in KIO::SlaveInterface::dispatch
(this=0x22c07d0) at ../../kio/kio/slaveinterface.cpp:89
#32 0x00007ffff2f681e6 in KIO::Slave::gotInput (this=0x22c07d0) at
../../kio/kio/slave.cpp:348
#33 0x00007ffff2f683cc in KIO::Slave::qt_metacall (this=0x22c07d0,
_c=QMetaObject::InvokeMetaMethod, _id=<value optimized out>,
_a=0x7fffffffb1e0) at ./slave.moc:82
#34 0x00007ffff5463b27 in QMetaObject::activate (sender=0x2481fd0,
m=<value optimized out>, local_signal_index=<value optimized out>,
argv=0x7ffff0af82a0) at kernel/qobject.cpp:3280
#35 0x00007ffff2e925d7 in KIO::ConnectionPrivate::dequeue
(this=0x2552a50) at ../../kio/kio/connection.cpp:82
#36 0x00007ffff2e926fd in KIO::Connection::qt_metacall
(this=0x2481fd0, _c=QMetaObject::InvokeMetaMethod, _id=<value
optimized out>, _a=0x1cb21d0) at ./connection.moc:79
#37 0x00007ffff545dbde in QObject::event (this=0x2481fd0, e=0x0) at
kernel/qobject.cpp:1219
#38 0x00007ffff5e2dfdc in QApplicationPrivate::notify_helper
(this=0x5c6a10, receiver=0x2481fd0, e=0x2242450) at
kernel/qapplication.cpp:4396
#39 0x00007ffff5e33aed in QApplication::notify (this=0x7fffffffbc90,
receiver=0x2481fd0, e=0x2242450) at kernel/qapplication.cpp:4277
#40 0x00007ffff79a7a36 in KApplication::notify (this=0x7fffffffbc90,
receiver=0x2481fd0, event=0x2242450) at
../../kdeui/kernel/kapplication.cpp:311
#41 0x00007ffff544bcdc in QCoreApplication::notifyInternal
(this=0x7fffffffbc90, receiver=0x2481fd0, event=0x2242450) at
kernel/qcoreapplication.cpp:732
#42 0x00007ffff544ec22 in sendEvent (receiver=0x0, event_type=<value
optimized out>, data=0x435660) at
../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:215
#43 QCoreApplicationPrivate::sendPostedEvents (receiver=0x0,
event_type=<value optimized out>, data=0x435660) at
kernel/qcoreapplication.cpp:1373
#44 0x00007ffff5478653 in sendPostedEvents (s=0x5c64e0) at
../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:220
#45 postEventSourceDispatch (s=0x5c64e0) at kernel/qeventdispatcher_glib.cpp:277
#46 0x00007fffee817342 in g_main_context_dispatch () from /lib/libglib-2.0.so.0
#47 0x00007fffee81b2a8 in ?? () from /lib/libglib-2.0.so.0
#48 0x00007fffee81b45c in g_main_context_iteration () from /lib/libglib-2.0.so.0
#49 0x00007ffff5478193 in QEventDispatcherGlib::processEvents
(this=0x434d10, flags=<value optimized out>) at
kernel/qeventdispatcher_glib.cpp:415
#50 0x00007ffff5ee0a4e in QGuiEventDispatcherGlib::processEvents
(this=0x0, flags=<value optimized out>) at
kernel/qguieventdispatcher_glib.cpp:204
#51 0x00007ffff544aa02 in QEventLoop::processEvents (this=<value
optimized out>, flags=DWARF-2 expression error: DW_OP_reg operations
must be used either alone or in conjuction with DW_OP_piece or
DW_OP_bit_piece.
) at kernel/qeventloop.cpp:149
#52 0x00007ffff544adec in QEventLoop::exec (this=0x7fffffffbc30,
flags=DWARF-2 expression error: DW_OP_reg operations must be used
either alone or in conjuction with DW_OP_piece or DW_OP_bit_piece.
) at kernel/qeventloop.cpp:201
#53 0x00007ffff544eebb in QCoreApplication::exec () at
kernel/qcoreapplication.cpp:1009
#54 0x000000000040ce3c in main (argc=4, argv=0x7fffffffe1b8) at
/home/mark/kde/src/amarok/src/main.cpp:282