This affects a lot more than emacs. I have had thunderbird and acroread both lockup repeatedly.

Here is the stack trace for acroread:
#0  0xf77b5425 in __kernel_vsyscall ()
#1  0xf5b5fdcb in poll () from /lib/i386-linux-gnu/libc.so.6
#2  0xf5dbe2db in g_poll () from /lib/i386-linux-gnu/libglib-2.0.so.0
#3  0xf5daf6d0 in ?? () from /lib/i386-linux-gnu/libglib-2.0.so.0
#4  0xf5dafc2b in g_main_loop_run () from /lib/i386-linux-gnu/libglib-2.0.so.0
#5  0xf5df5c21 in g_spawn_sync () from /lib/i386-linux-gnu/libglib-2.0.so.0
#6  0xf5df6094 in g_spawn_command_line_sync () from /lib/i386-linux-gnu/libglib-2.0.so.0
#7  0xf332be4c in Oxygen::QtSettings::kdeConfigPathList() const ()
   from /usr/lib/i386-linux-gnu/gtk-2.0/2.10.0/engines/liboxygen-gtk.so
#8  0xf332e8f3 in Oxygen::QtSettings::initialize(unsigned int) ()
   from /usr/lib/i386-linux-gnu/gtk-2.0/2.10.0/engines/liboxygen-gtk.so
#9  0xf3341b18 in Oxygen::Style::initialize(unsigned int) () from /usr/lib/i386-linux-gnu/gtk-2.0/2.10.0/engines/liboxygen-gtk.so
#10 0xf3341ef3 in Oxygen::Style::fileChanged(_GFileMonitor*, _GFile*, _GFile*, GFileMonitorEvent, void*) ()
   from /usr/lib/i386-linux-gnu/gtk-2.0/2.10.0/engines/liboxygen-gtk.so
#11 0xf4c4e48e in ffi_call_SYSV () from /usr/lib/i386-linux-gnu/libffi.so.6
#12 0xf4c4e1ef in ffi_call () from /usr/lib/i386-linux-gnu/libffi.so.6
#13 0xf5e77a2a in g_cclosure_marshal_generic_va () from /usr/lib/i386-linux-gnu/libgobject-2.0.so.0
#14 0xf5e76ee1 in ?? () from /usr/lib/i386-linux-gnu/libgobject-2.0.so.0
#15 0xf5e9065a in g_signal_emit_valist () from /usr/lib/i386-linux-gnu/libgobject-2.0.so.0
#16 0xf5e91233 in g_signal_emit () from /usr/lib/i386-linux-gnu/libgobject-2.0.so.0
#17 0xf4d39229 in ?? () from /usr/lib/i386-linux-gnu/libgio-2.0.so.0
#18 0xf5dabf10 in ?? () from /lib/i386-linux-gnu/libglib-2.0.so.0
#19 0xf5daf3b3 in g_main_context_dispatch () from /lib/i386-linux-gnu/libglib-2.0.so.0
#20 0xf5daf750 in ?? () from /lib/i386-linux-gnu/libglib-2.0.so.0
#21 0xf5dafc2b in g_main_loop_run () from /lib/i386-linux-gnu/libglib-2.0.so.0
#22 0xf612c710 in gtk_main () from /usr/lib/i386-linux-gnu/libgtk-x11-2.0.so.0
#23 0x0850d0bd in _start ()

Here is the trace for thunderbird:
#0  0x00007f9b459483cd in poll () at ../sysdeps/unix/syscall-template.S:81
#1  0x00007f9b404501dc in g_main_context_poll (n_fds=1, fds=0x7f9af37f6d28, timeout=-1, context=0x7f9af37a7680, 
    priority=<optimized out>) at /build/buildd/glib2.0-2.36.0/./glib/gmain.c:3995
#2  g_main_context_iterate (context=0x7f9af37a7680, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>)
    at /build/buildd/glib2.0-2.36.0/./glib/gmain.c:3696
#3  0x00007f9b404506ba in g_main_loop_run (loop=0x7f9afb710370) at /build/buildd/glib2.0-2.36.0/./glib/gmain.c:3895
#4  0x00007f9b40491e41 in g_spawn_sync (working_directory=working_directory@entry=0x0, argv=<optimized out>, envp=envp@entry=0x0, 
    flags=flags@entry=G_SPAWN_SEARCH_PATH, child_setup=child_setup@entry=0x0, user_data=user_data@entry=0x0, 
    standard_output=standard_output@entry=0x7fff584be268, standard_error=standard_error@entry=0x0, 
    exit_status=exit_status@entry=0x0, error=error@entry=0x0) at /build/buildd/glib2.0-2.36.0/./glib/gspawn.c:434
#5  0x00007f9b404922b8 in g_spawn_command_line_sync (command_line=<optimized out>, standard_output=0x7fff584be268, 
    standard_error=0x0, exit_status=0x0, error=0x0) at /build/buildd/glib2.0-2.36.0/./glib/gspawn.c:735
#6  0x00007f9b36fe1184 in Oxygen::QtSettings::kdeConfigPathList() const ()
   from /usr/lib/x86_64-linux-gnu/gtk-2.0/2.10.0/engines/liboxygen-gtk.so
#7  0x00007f9b36fe3ca7 in Oxygen::QtSettings::initialize(unsigned int) ()
   from /usr/lib/x86_64-linux-gnu/gtk-2.0/2.10.0/engines/liboxygen-gtk.so
#8  0x00007f9b36ff5485 in Oxygen::Style::initialize(unsigned int) ()
   from /usr/lib/x86_64-linux-gnu/gtk-2.0/2.10.0/engines/liboxygen-gtk.so
#9  0x00007f9b36ff57f1 in Oxygen::Style::fileChanged(_GFileMonitor*, _GFile*, _GFile*, GFileMonitorEvent, void*) ()
   from /usr/lib/x86_64-linux-gnu/gtk-2.0/2.10.0/engines/liboxygen-gtk.so
#10 0x00007f9b42bcf138 in ffi_call_unix64 () from /usr/lib/thunderbird/libxul.so
#11 0x00007f9b42bceb50 in ffi_call (cif=cif@entry=0x7fff584be6b0, 
    fn=fn@entry=0x7f9b36ff57e0 <Oxygen::Style::fileChanged(_GFileMonitor*, _GFile*, _GFile*, GFileMonitorEvent, void*)>, 
    rvalue=0x7fff584be5e0, avalue=avalue@entry=0x7fff584be560)
    at /build/buildd/thunderbird-17.0.5+build1/./mozilla/js/src/ctypes/libffi/src/x86/ffi64.c:485
#12 0x00007f9b4071460b in g_cclosure_marshal_generic_va (closure=0x7f9b366168f0, return_value=0x0, instance=0x7f9b36619940, 
    args_list=<optimized out>, 
    marshal_data=0x7f9b36ff57e0 <Oxygen::Style::fileChanged(_GFileMonitor*, _GFile*, _GFile*, GFileMonitorEvent, void*)>, 
    n_params=3, param_types=0x7f9b36621840) at /build/buildd/glib2.0-2.36.0/./gobject/gclosure.c:1550
#13 0x00007f9b407138e7 in _g_closure_invoke_va (closure=0x7f9b366168f0, return_value=0x0, instance=0x7f9b36619940, 
    args=0x7fff584be9e8, n_params=3, param_types=0x7f9b36621840) at /build/buildd/glib2.0-2.36.0/./gobject/gclosure.c:840
#14 0x00007f9b4072c2df in g_signal_emit_valist (instance=0x7f9b36619940, signal_id=<optimized out>, detail=0, 
    var_args=var_args@entry=0x7fff584be9e8) at /build/buildd/glib2.0-2.36.0/./gobject/gsignal.c:3234
#15 0x00007f9b4072cf92 in g_signal_emit (instance=instance@entry=0x7f9b36619940, signal_id=<optimized out>, detail=detail@entry=0)
    at /build/buildd/glib2.0-2.36.0/./gobject/gsignal.c:3384
#16 0x00007f9b3e512871 in emit_cb (data=0x7f9b36619940) at /build/buildd/glib2.0-2.36.0/./gio/gfilemonitor.c:396
#17 0x00007f9b4044ff05 in g_main_dispatch (context=0x7f9b4552aa80) at /build/buildd/glib2.0-2.36.0/./glib/gmain.c:3054
#18 g_main_context_dispatch (context=context@entry=0x7f9b4552aa80) at /build/buildd/glib2.0-2.36.0/./glib/gmain.c:3630
#19 0x00007f9b40450248 in g_main_context_iterate (context=context@entry=0x7f9b4552aa80, block=block@entry=1, 
    dispatch=dispatch@entry=1, self=<optimized out>) at /build/buildd/glib2.0-2.36.0/./glib/gmain.c:3701
#20 0x00007f9b40450304 in g_main_context_iteration (context=0x7f9b4552aa80, may_block=1)
    at /build/buildd/glib2.0-2.36.0/./glib/gmain.c:3762
#21 0x00007f9b422cbd4a in nsAppShell::ProcessNextNativeEvent (this=<optimized out>, mayWait=<optimized out>)
    at /build/buildd/thunderbird-17.0.5+build1/mozilla/widget/gtk2/nsAppShell.cpp:131
#22 0x00007f9b422e1d07 in nsBaseAppShell::DoProcessNextNativeEvent (this=this@entry=0x7f9b315c0470, mayWait=<optimized out>, 
    recursionDepth=recursionDepth@entry=0)
    at /build/buildd/thunderbird-17.0.5+build1/mozilla/widget/xpwidgets/nsBaseAppShell.cpp:139
#23 0x00007f9b422e1e20 in nsBaseAppShell::OnProcessNextEvent (this=0x7f9b315c0470, thr=0x7f9b45527420, mayWait=<optimized out>, 
    recursionDepth=0) at /build/buildd/thunderbird-17.0.5+build1/mozilla/widget/xpwidgets/nsBaseAppShell.cpp:298
#24 0x00007f9b4267b99b in nsThread::ProcessNextEvent (this=0x7f9b45527420, mayWait=<optimized out>, result=0x7fff584becdf)
    at /build/buildd/thunderbird-17.0.5+build1/mozilla/xpcom/threads/nsThread.cpp:586
#25 0x00007f9b42651917 in NS_ProcessNextEvent_P (thread=<optimized out>, mayWait=mayWait@entry=true)
    at /build/buildd/thunderbird-17.0.5+build1/obj-x86_64-linux-gnu/mozilla/xpcom/build/nsThreadUtils.cpp:220
#26 0x00007f9b4259a123 in mozilla::ipc::MessagePump::Run (this=0x7f9b31512ac0, aDelegate=0x7f9b366a16f0)
    at /build/buildd/thunderbird-17.0.5+build1/mozilla/ipc/glue/MessagePump.cpp:117
#27 0x00007f9b4269a369 in RunHandler (this=0x7f9b366a16f0)
    at /build/buildd/thunderbird-17.0.5+build1/mozilla/ipc/chromium/src/base/message_loop.cc:201
#28 MessageLoop::Run (this=0x7f9b366a16f0)
    at /build/buildd/thunderbird-17.0.5+build1/mozilla/ipc/chromium/src/base/message_loop.cc:175
#29 0x00007f9b422e16f7 in nsBaseAppShell::Run (this=0x7f9b315c0470)
    at /build/buildd/thunderbird-17.0.5+build1/mozilla/widget/xpwidgets/nsBaseAppShell.cpp:163
#30 0x00007f9b421bfb49 in nsAppStartup::Run (this=0x7f9b2f883100)
    at /build/buildd/thunderbird-17.0.5+build1/mozilla/toolkit/components/startup/nsAppStartup.cpp:273
#31 0x00007f9b419e71a8 in XREMain::XRE_mainRun (this=this@entry=0x7fff584bef10)
    at /build/buildd/thunderbird-17.0.5+build1/mozilla/toolkit/xre/nsAppRunner.cpp:3812
#32 0x00007f9b419e915e in XREMain::XRE_main (this=this@entry=0x7fff584bef10, argc=argc@entry=1, argv=argv@entry=0x7fff584c02f8, 
    aAppData=aAppData@entry=0x7f9b45523780) at /build/buildd/thunderbird-17.0.5+build1/mozilla/toolkit/xre/nsAppRunner.cpp:3889
#33 0x00007f9b419e939a in XRE_main (argc=1, argv=0x7fff584c02f8, aAppData=0x7f9b45523780, aFlags=<optimized out>)
    at /build/buildd/thunderbird-17.0.5+build1/mozilla/toolkit/xre/nsAppRunner.cpp:3965
#34 0x00000000004022e4 in do_main (argv=0x7fff584c02f8, argc=1, exePath=0x7fff584bf1d8 "/usr/lib/thunderbird/")
    at /build/buildd/thunderbird-17.0.5+build1/mail/app/nsMailApp.cpp:111
#35 main (argc=1, argv=0x7fff584c02f8) at /build/buildd/thunderbird-17.0.5+build1/mail/app/nsMailApp.cpp:200