pthread_mutex_lock problem

[SoAnIs]

I recently tried installing kubuntu-kde4-desktop, this didn't work (dbus issue.) Now, all my qt4 apps fail, with the following error:
lyx: pthread_mutex_lock.c:87: __pthread_mutex_lock: Assertion `mutex->__data.__owner == 0' failed.
Aborted

Backtrace of lyx:
GNU gdb 6.8-debian
Copyright (C) 2008 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law. Type "show copying"
and "show warranty" for details.
This GDB was configured as "x86_64-linux-gnu"...
(gdb) handle SIG33 pass snostop noprint
Signal Stop Print Pass to program Description
SIG33 No No Yes Real-time event 33
(gdb) set pagination 0
(gdb) run lixyx
Starting program: /usr/bin/lyx
[Thread debugging using libthread_db enabled]
warning: Lowest section in /usr/lib/libicudata.so.38 is .hash at 0000000000000120
[New Thread 0x7fcb9b728780 (LWP 1594)]
lyx: pthread_mutex_lock.c:87: __pthread_mutex_lock: Assertion `mutex->__data.__owner == 0' failed.

Program received signal SIGABRT, Aborted.
[Switching to Thread 0x7fcb9b728780 (LWP 1594)]
0x00007fcb98966095 in raise () from /lib/libc.so.6
(gdb) backtrace uffull
#0 0x00007fcb98966095 in raise () from /lib/libc.so.6
No symbol table info available.
#1 0x00007fcb98967af0 in abort () from /lib/libc.so.6
No symbol table info available.
#2 0x00007fcb9895f2df in __assert_fail () from /lib/libc.so.6
No symbol table info available.
#3 0x00007fcb9a501ac7 in pthread_mutex_lock () from /lib/libpthread.so.0
No symbol table info available.
#4 0x00007fcb977db298 in g_source_attach () from /usr/lib/libglib-2.0.so.0
No symbol table info available.
#5 0x00007fcb9ad68eee in ?? () from /usr/lib/libQtGui.so.4
No symbol table info available.
#6 0x00007fcb9ad3c39e in QApplicationPrivate::createEventDispatcher () from /usr/lib/libQtGui.so.4
No symbol table info available.
#7 0x00007fcb9a86630f in QCoreApplication::init () from /usr/lib/libQtCore.so.4
No symbol table info available.
#8 0x00007fcb9a86654f in QCoreApplication::QCoreApplication () from /usr/lib/libQtCore.so.4
No symbol table info available.
#9 0x00007fcb9acf9534 in QApplication::QApplication () from /usr/lib/libQtGui.so.4
No symbol table info available.
#10 0x00000000007bcb54 in GuiApplication (this=0x63a, argc=@0x63a, argv=0x6) at ../../../../src/frontends/qt4/GuiApplication.cpp:105
No locals.
#11 0x00000000007bd8f4 in lyx::createApplication (argc=@0x7fffa375bb9c, argv=0x7fffa375bcb8) at ../../../../src/frontends/qt4/GuiApplication.cpp:89
No locals.
#12 0x0000000000540880 in lyx::LyX::exec (this=0x7fffa375bba0, argc=@0x7fffa375bb9c, argv=0x7fffa375bcb8) at ../../src/LyX.cpp:451
exit_status = <value optimized out>
#13 0x000000000042f4b3 in main (argc=1, argv=0x7fffa375bcb8) at ../../src/main.cpp:48
the_lyx_instance = {<boost::noncopyable_::noncopyable> = {<No data fields>}, first_start = false, batch_command = {static npos = 18446744073709551615, _M_dataplus = {<std::allocator<char>> = {<__gnu_cxx::new_allocator<char>> = {<No data fields>}, <No data fields>}, _M_p = 0xcfc198 ""}}, pimpl_ = {ptr = 0xd83240}}
(gdb) info registers
rax 0x0 0
rbx 0x7fffa375b600 140735935788544
rcx 0xffffffffffffffff -1
rdx 0x6 6
rsi 0x63a 1594
rdi 0x63a 1594
rbp 0x7fcb9b728780 0x7fcb9b728780
rsp 0x7fffa375b558 0x7fffa375b558
r8 0x0 0
r9 0x203d3d2072656e77 2323080192360541815
r10 0x8 8
r11 0x206 518
r12 0x7fffa375c7b6 140735935793078
r13 0x7fcb9a509535 140512444060981
r14 0x57 87
r15 0x7fcb9a509cb6 140512444062902
rip 0x7fcb98966095 0x7fcb98966095 <raise+53>
eflags 0x206 [ PF IF ]
cs 0x33 51
ss 0x2b 43
ds 0x0 0
es 0x0 0
fs 0x0 0
gs 0x0 0
fctrl 0x37f 895
fstat 0x0 0
ftag 0xffff 65535
fiseg 0x0 0
fioff 0x0 0
foseg 0x0 0
fooff 0x0 0
fop 0x0 0
mxcsr 0x1f80 [ IM DM ZM OM UM PM ]
(gdb) thread apply all backtrace

Thread 1 (Thread 0x7fcb9b728780 (LWP 1594)):
#0 0x00007fcb98966095 in raise () from /lib/libc.so.6
#1 0x00007fcb98967af0 in abort () from /lib/libc.so.6
#2 0x00007fcb9895f2df in __assert_fail () from /lib/libc.so.6
#3 0x00007fcb9a501ac7 in pthread_mutex_lock () from /lib/libpthread.so.0
#4 0x00007fcb977db298 in g_source_attach () from /usr/lib/libglib-2.0.so.0
#5 0x00007fcb9ad68eee in ?? () from /usr/lib/libQtGui.so.4
#6 0x00007fcb9ad3c39e in QApplicationPrivate::createEventDispatcher () from /usr/lib/libQtGui.so.4
#7 0x00007fcb9a86630f in QCoreApplication::init () from /usr/lib/libQtCore.so.4
#8 0x00007fcb9a86654f in QCoreApplication::QCoreApplication () from /usr/lib/libQtCore.so.4
#9 0x00007fcb9acf9534 in QApplication::QApplication () from /usr/lib/libQtGui.so.4
#10 0x00000000007bcb54 in GuiApplication (this=0x63a, argc=@0x63a, argv=0x6) at ../../../../src/frontends/qt4/GuiApplication.cpp:105
#11 0x00000000007bd8f4 in lyx::createApplication (argc=@0x7fffa375bb9c, argv=0x7fffa375bcb8) at ../../../../src/frontends/qt4/GuiApplication.cpp:89
#12 0x0000000000540880 in lyx::LyX::exec (this=0x7fffa375bba0, argc=@0x7fffa375bb9c, argv=0x7fffa375bcb8) at ../../src/LyX.cpp:451
#13 0x000000000042f4b3 in main (argc=1, argv=0x7fffa375bcb8) at ../../src/main.cpp:48
(gdb) quit
The program is running. Exit anyway? (y or n)