Couldn't find the appropriate bug report so I'm posting this here. Something tells me it's not an actual bug but a misconfig in the system which just needs some tweaking. Here's the problem.

After having added clips in the project tree, switching from previewing a clip to the next before the last one finishes playing (and sometimes after it has stopped) crashes kdenlive with Signal: 11 (Segmentation fault). If I don't manually save the project after each time I make a change I usually lose all progress as it crashes at least twice every five minutes.

EDIT: After installing the newest version the problem stopped.

Crash info:
Application: Kdenlive (kdenlive), signal: Segmentation fault
[Current thread is 1 (Thread 0xb778d930 (LWP 10945))]

Thread 4 (Thread 0xb5207b70 (LWP 10946)):
#0 0x0027e344 in __pthread_mutex_unlock_usercnt () from /lib/tls/i686/cmov/libpthread.so.0
#1 0x01224bb8 in g_main_context_prepare () from /lib/libglib-2.0.so.0
#2 0x01224fe9 in ?? () from /lib/libglib-2.0.so.0
#3 0x012255b8 in g_main_context_iteration () from /lib/libglib-2.0.so.0
#4 0x0108374f in QEventDispatcherGlib::processEvents (this=0x98b47b8, flags=...) at kernel/qeventdispatcher_glib.cpp:414
#5 0x01056149 in QEventLoop::processEvents (this=0xb5207290, flags=) at kernel/qeventloop.cpp:149
#6 0x0105659a in QEventLoop::exec (this=0xb5207290, flags=...) at kernel/qeventloop.cpp:201
#7 0x00f52778 in QThread::exec (this=0x98b2328) at thread/qthread.cpp:487
#8 0x01035d0b in QInotifyFileSystemWatcherEngine::run (this=0x98b2328) at io/qfilesystemwatcher_inotify.cpp:248
#9 0x00f554fe in QThreadPrivate::start (arg=0x98b2328) at thread/qthread_unix.cpp:248
#10 0x0027a96e in start_thread () from /lib/tls/i686/cmov/libpthread.so.0
#11 0x077253fe in clone () from /lib/tls/i686/cmov/libc.so.6

Thread 3 (Thread 0xb18fcb70 (LWP 11053)):
[KCrash Handler]
#6 0x09080770 in ?? () from /usr/lib/i686/cmov/libswscale.so.0

Thread 2 (Thread 0xab4f4b70 (LWP 11054)):
#0 0x00c29422 in __kernel_vsyscall ()
#1 0x0027f015 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/tls/i686/cmov/libpthread.so.0
#2 0x030ab49f in ?? () from /usr/lib/mlt/libmltsdl.so
Backtrace stopped: previous frame inner to this frame (corrupt stack?)

Thread 1 (Thread 0xb778d930 (LWP 10945)):
#0 0x00c29422 in __kernel_vsyscall ()
#1 0x00281af9 in __lll_lock_wait () from /lib/tls/i686/cmov/libpthread.so.0
#2 0x0027d13b in _L_lock_748 () from /lib/tls/i686/cmov/libpthread.so.0
#3 0x0027cf61 in pthread_mutex_lock () from /lib/tls/i686/cmov/libpthread.so.0
#4 0x019f78dd in avformat_lock () from /usr/lib/mlt/libmltavformat.so
#5 0x076c4c7d in free () from /lib/tls/i686/cmov/libc.so.6
Backtrace stopped: previous frame inner to this frame (corrupt stack?)