Thanks for your report, and sorry for the long (!) delay.

Setting up man-db (2.5.7-4) ...
Installing new version of config file /etc/cron.daily/man-db ...
Installing new version of config file /etc/cron.weekly/man-db ...
*** glibc detected *** /usr/bin/perl: realloc(): invalid next size: 0x09ff3438 ***
======= Backtrace: =========
/lib/libc.so.6(+0x6c501)[0x34e501]
/lib/libc.so.6(+0x71c6d)[0x353c6d]
/lib/libc.so.6(realloc+0xe3)[0x353f53]
/usr/lib/libX11.so.6(+0x4a87f)[0x91987f]
/usr/lib/libX11.so.6(+0x4a9ed)[0x9199ed]
/usr/lib/libX11.so.6(_XlcCreateLocaleDataBase+0x1d5)[0x91a7a5]
/usr/lib/libX11.so.6(+0x50bd7)[0x91fbd7]
/usr/lib/libX11.so.6(+0x50133)[0x91f133]
/usr/lib/libX11.so.6(_XlcCreateLC+0x45)[0x91f8a5]
/usr/lib/libX11.so.6(_XlcUtf8Loader+0x2a)[0x943d4a]
/usr/lib/libX11.so.6(_XOpenLC+0x114)[0x927894]
/usr/lib/libX11.so.6(_XlcCurrentLC+0x23)[0x927a03]
/usr/lib/libX11.so.6(XSupportsLocale+0x17)[0x927cb7]
/usr/lib/libgdk-x11-2.0.so.0(+0x59333)[0x7f2333]
/usr/lib/libgdk-x11-2.0.so.0(+0x5e7d7)[0x7f77d7]
/usr/lib/libgdk-x11-2.0.so.0(gdk_pre_parse_libgtk_only+0x6d)[0x7ade2d]
/usr/lib/libgtk-x11-2.0.so.0(+0x12fa42)[0x144aa42]
/lib/libglib-2.0.so.0(g_option_context_parse+0xaf)[0x62dd7f]
/usr/lib/libgtk-x11-2.0.so.0(gtk_parse_args+0xac)[0x144a71c]
/usr/lib/libgtk-x11-2.0.so.0(gtk_init_check+0x24)[0x144a794]
/usr/lib/libgtk-x11-2.0.so.0(gtk_init+0x24)[0x144a7d4]
/usr/lib/libbonoboui-2.so.0(+0x20aa5)[0x7294aa5]
/usr/lib/libgnome-2.so.0(gnome_program_postinit+0xa0)[0xbc9920]
/usr/lib/libgnome-2.so.0(+0xbd72)[0xbc9d72]
/usr/lib/perl5/auto/Gnome2/Gnome2.so(XS_Gnome2__Program_init+0x1e8)[0x88ec7e8]
/usr/bin/perl(Perl_pp_entersub+0x52b)[0x80d5d4b]
/usr/bin/perl(Perl_runops_standard+0x18)[0x80d4118]
/usr/bin/perl(perl_run+0x342)[0x807cef2]
/usr/bin/perl(main+0xed)[0x80643ad]
/lib/libc.so.6(__libc_start_main+0xe7)[0x2f8ce7]
/usr/bin/perl[0x8064221]
======= Memory map: ========
00110000-0011a000 r-xp 00000000 08:01 2230507    /lib/libnss_files-2.12.1.so
0011a000-0011b000 r--p 00009000 08:01 2230507    /lib/libnss_files-2.12.1.so
0011b000-0011c000 rw-p 0000a000 08:01 2230507    /lib/libnss_files-2.12.1.so
0011c000-0011f000 r-xp 00000000 08:01 134226     /usr/lib/libgthread-2.0.so.0.2600.0
0011f000-00120000 r--p 00003000 08:01 134226     /usr/lib/libgthread-2.0.so.0.2600.0
00120000-00121000 rw-p 00004000 08:01 134226     /usr/lib/libgthread-2.0.so.0.2600.0
00121000-00128000 r-xp 00000000 08:01 2230511    /lib/librt-2.12.1.so
00128000-00129000 r--p 00006000 08:01 2230511    /lib/librt-2.12.1.so
00129000-0012a000 rw-p 00007000 08:01 2230511    /lib/librt-2.12.1.so
0012a000-00130000 r-xp 00000000 08:01 133925     /usr/lib/libxcb-render.so.0.0.0
00130000-00131000 r--p 00005000 08:01 133925     /usr/lib/libxcb-render.so.0.0.0
00131000-00132000 rw-p 00006000 08:01 133925     /usr/lib/libxcb-render.so.0.0.0
00132000-0014a000 r-xp 00000000 08:01 133940     /usr/lib/libxcb.so.1.1.0
0014a000-0014b000 r--p 00017000 08:01 133940     /usr/lib/libxcb.so.1.1.0
0014b000-0014c000 rw-p 00018000 08:01 133940     /usr/lib/libxcb.so.1.1.0
0014e000-00157000 r-xp 00000000 08:01 394065     /usr/lib/perl/5.10.1/auto/List/Util/Util.so
00157000-00158000 r--p 00008000 08:01 394065     /usr/lib/perl/5.10.1/auto/List/Util/Util.so
00158000-00159000 rw-p 00009000 08:01 394065     /usr/lib/perl/5.10.1/auto/List/Util/Util.so
00159000-00161000 r-xp 00000000 08:01 137952     /usr/lib/libXrender.so.1.3.0
00161000-00162000 r--p 00007000 08:01 137952     /usr/lib/libXrender.so.1.3.0
00162000-00163000 rw-p 00008000 08:01 137952     /usr/lib/libXrender.so.1.3.0
00163000-00165000 r-xp 00000000 08:01 134667     /usr/lib/libXau.so.6.0.0
00165000-00166000 r--p 00001000 08:01 134667     /usr/lib/libXau.so.6.0.0
00166000-00167000 rw-p 00002000 08:01 134667     /usr/lib/libXau.so.6.0.0
0016a000-0016c000 r-xp 00000000 08:01 134934     /usr/lib/libxcb-shm.so.0.0.0
0016c000-0016d000 r--p 00001000 08:01 134934     /usr/lib/libxcb-shm.so.0.0.0
0016d000-0016e000 rw-p 00002000 08:01 134934     /usr/lib/libxcb-shm.so.0.0.0
0016e000-00170000 r-xp 00000000 08:01 134225     /usr/lib/libgmodule-2.0.so.0.2600.0
00170000-00171000 r--p 00002000 08:01 134225     /usr/lib/libgmodule-2.0.so.0.2600.0
00171000-00172000 rw-p 00003000 08:01 134225     /usr/lib/libgmodule-2.0.so.0.2600.0
00174000-0017d000 r-xp 00000000 08:01 2230513    /lib/libnss_nis-2.12.1.so
0017d000-0017e000 r--p 00008000 08:01 2230513    /lib/libnss_nis-2.12.1.so
0017e000-0017f000 rw-p 00009000 08:01 2230513    /lib/libnss_nis-2.12.1.so
0017f000-001bf000 r-xp 00000000 08:01 131963     /usr/lib/libgobject-2.0.so.0.2600.0
001bf000-001c0000 r--p 00040000 08:01 131963     /usr/lib/libgobject-2.0.so.0.2600.0
001c0000-001c1000 rw-p 00041000 08:01 131963     /usr/lib/libgobject-2.0.so.0.2600.0
001c1000-001f4000 r-xp 00000000 08:01 2228316    /lib/libpcre.so.3.12.1
001f4000-001f5000 r--p 00032000 08:01 2228316    /lib/libpcre.so.3.12.1
001f5000-001f6000 rw-p 00033000 08:01 2228316    /lib/libpcre.so.3.12.1
001f6000-00233000 r-xp 00000000 08:01 393281     /usr/lib/perl5/auto/Cairo/Cairo.so
00233000-00234000 r--p 0003d000 08:01 393281     /usr/lib/perl5/auto/Cairo/Cairo.so
00234000-00235000 rw-p 0003e000 08:01 393281     /usr/lib/perl5/auto/Cairo/Cairo.so
00235000-00248000 r-xp 00000000 08:01 2228277    /lib/libz.so.1.2.3.4
00248000-00249000 r--p 00012000 08:01 2228277    /lib/libz.so.1.2.3.4
00249000-0024a000 rw-p 00013000 08:01 2228277    /lib/libz.so.1.2.3.4
0024a000-00261000 r-xp 00000000 08:01 134424     /usr/lib/libgdk_pixbuf-2.0.so.0.2200.0
00261000-00262000 r--p 00017000 08:01 134424     /usr/lib/libgdk_pixbuf-2.0.so.0.2200.0
00262000-00263000 rw-p 00018000 08:01 134424     /usr/lib/libgdk_pixbuf-2.0.so.0.2200.0
00263000-00265000 r-xp 00000000 08:01 2230509    /lib/libdl-2.12.1.so
00265000-00266000 r--p 00001000 08:01 2230509    /lib/libdl-2.12.1.so
00266000-00267000 rw-p 00002000 08:01 2230509    /lib/libdl-2.12.1.so
00267000-00269000 r-xp 00000000 08:01 133950     /usr/lib/libXinerama.so.1.0.0
00269000-0026a000 r--p 00001000 08:01 133950     /usr/lib/libXinerama.so.1.0.0
0026a000-0026b000 rw-p 00002000 08:01 133950     /usr/lib/libXinerama.so.1.0.0
0026d000-00271000 r-xp 00000000 08:01 394064     /usr/lib/perl/5.10.1/auto/IO/IO.so
00271000-00272000 r--p 00003000 08:01 394064     /usr/lib/perl/5.10.1/auto/IO/IO.so
00272000-00273000 rw-p 00004000 08:01 394064     /usr/lib/perl/5.10.1/auto/IO/IO.so
00273000-002a1000 r-xp 00000000 08:01 134222     /usr/lib/libfontconfig.so.1.4.4
002a1000-002a2000 r--p 0002d000 08:01 134222     /usr/lib/libfontconfig.so.1.4.4
002a2000-002a3000 rw-p 0002e000 08:01 134222     /usr/lib/libfontconfig.so.1.4.4
002a3000-002c7000 r-xp 00000000 08:01 2228300    /lib/libexpat.so.1.5.2
002c7000-002c9000 r--p 00024000 08:01 2228300    /lib/libexpat.so.1.5.2
002c9000-002ca000 rw-p 00026000 08:01 2228300    /lib/libexpat.so.1.5.2
002ca000-002d8000 r-xp 00000000 08:01 134137     /usr/lib/libXext.so.6.4.0
002d8000-002d9000 r--p 0000d000 08:01 134137     /usr/lib/libXext.so.6.4.0
002d9000-002da000 rw-p 0000e000 08:01 134137     /usr/lib/libXext.so.6.4.0
002da000-002dc000 r-xp 00000000 08:01 133944     /usr/lib/libXcomposite.so.1.0.0
002dc000-002dd000 r--p 00001000 08:01 133944     /usr/lib/libXcomposite.so.1.0.0
002dd000-002de000 rw-p 00002000 08:01 133944     /usr/lib/libXcomposite.so.1.0.0dpkg: error processing man-db (--configure):
 subprocess installed post-installation script killed by signal (Aborted)

This doesn't look like a man-db bug, but rather some problem in (probably) debconf's GNOME frontend that man-db ran into when trying to use debconf.  That frontend has since been rewritten to use GTK+ 3, so I think whatever this was has almost certainly been fixed in the intervening years.