When I tried to start alarm-clock in command line, I got this:

alarm-clock 
*** glibc detected *** /usr/bin/python: double free or corruption (fasttop): 0x0000000001e01280 ***
======= Backtrace: =========
/lib/libc.so.6[0x7f78da0aad48]
/lib/libc.so.6(cfree+0x76)[0x7f78da0ad306]
/usr/lib/libX11.so.6[0x7f78d5bc99a6]
/usr/lib/libX11.so.6(_XReply+0x138)[0x7f78d5bc9fd8]
/usr/lib/libX11.so.6(XQueryPointer+0x8f)[0x7f78d5bb797f]
/usr/lib/libgdk-x11-2.0.so.0[0x7f78d7787d36]
/usr/lib/libgdk-x11-2.0.so.0(gdk_display_get_window_at_pointer+0x94)[0x7f78d773bff4]
/usr/lib/libgtk-x11-2.0.so.0(gtk_tooltip_trigger_tooltip_query+0x23)[0x7f78d7bfc6b3]
/usr/lib/libgobject-2.0.so.0(g_object_set_valist+0x377)[0x7f78d93ce597]
/usr/lib/libgobject-2.0.so.0(g_object_set+0xe4)[0x7f78d93cea24]
/var/lib/python-support/python2.5/gtk-2.0/gtk/_gtk.so[0x7f78d80d2a90]
/usr/bin/python(PyEval_EvalFrameEx+0x4ea5)[0x4908a5]
/usr/bin/python(PyEval_EvalFrameEx+0x59b2)[0x4913b2]
/usr/bin/python(PyEval_EvalFrameEx+0x59b2)[0x4913b2]
/usr/bin/python(PyEval_EvalFrameEx+0x59b2)[0x4913b2]
/usr/bin/python(PyEval_EvalCodeEx+0x6ad)[0x491b9d]
/usr/bin/python[0x4dc982]
/usr/bin/python(PyObject_Call+0x13)[0x418c73]
/usr/bin/python[0x41fb48]
/usr/bin/python(PyObject_Call+0x13)[0x418c73]
/usr/bin/python(PyEval_CallObjectWithKeywords+0x72)[0x48a9e2]
/usr/bin/python[0x4bdbdd]
/lib/libpthread.so.0[0x7f78daa383ba]
/lib/libc.so.6(clone+0x6d)[0x7f78da1190ad]
======= Memory map: ========
00400000-00524000 r-xp 00000000 08:02 1529                               /usr/bin/python2.5
00723000-00724000 r--p 00123000 08:02 1529                               /usr/bin/python2.5
00724000-00756000 rw-p 00124000 08:02 1529                               /usr/bin/python2.5
00756000-0075e000 rw-p 00756000 00:00 0 
00e7c000-0229b000 rw-p 00e7c000 00:00 0                                  [heap]
7f78a05dc000-7f78a05dd000 rw-p 7f78a05dc000 00:00 0 
7f78a05dd000-7f78a063d000 rw-s 00000000 00:09 3211283                    /SYSV00000000 (deleted)
7f78a063d000-7f78a063e000 ---p 7f78a063d000 00:00 0 
7f78a063e000-7f78a0e3e000 rwxp 7f78a063e000 00:00 0 
7f78a0e3e000-7f78a0e9e000 rw-s 00000000 00:09 3178514                    /SYSV00000000 (deleted)
7f78a0e9e000-7f78a0ea2000 r-xp 00000000 08:02 73337                      /usr/lib/gtk-2.0/2.10.0/loaders/libpixbufloader-png.so
7f78a0ea2000-7f78a10a2000 ---p 00004000 08:02 73337                      /usr/lib/gtk-2.0/2.10.0/loaders/libpixbufloader-png.so
7f78a10a2000-7f78a10a3000 r--p 00004000 08:02 73337                      /usr/lib/gtk-2.0/2.10.0/loaders/libpixbufloader-png.so
7f78a10a3000-7f78a10a4000 rw-p 00005000 08:02 73337                      /usr/lib/gtk-2.0/2.10.0/loaders/libpixbufloader-png.so
7f78a10a4000-7f78a10bc000 r--s 00000000 08:02 13299                      /usr/share/mime/mime.cache
7f78a10bc000-7f78a10bd000 r--s 00000000 08:02 401954                     /usr/local/share/mime/mime.cache
7f78a10bd000-7f78a10be000 r--s 00000000 08:06 1047556                    /home/ming/.local/share/mime/mime.cache
7f78a10be000-7f78a1550000 r--p 00000000 08:02 63853                      /usr/share/icons/hicolor/icon-theme.cache
7f78a1550000-7f78a15e5000 r--p 00000000 08:02 20611                      /usr/share/fonts/truetype/ttf-dejavu/DejaVuSans.ttf
7f78a15e5000-7f78a15e7000 r-xp 00000000 08:02 21724                      /usr/lib/pango/1.6.0/modules/pango-basic-fc.so
7f78a15e7000-7f78a17e6000 ---p 00002000 08:02 21724                      /usr/lib/pango/1.6.0/modules/pango-basic-fc.so
7f78a17e6000-7f78a17e7000 r--p 00001000 08:02 21724                      /usr/lib/pango/1.6.0/modules/pango-basic-fc.so
7f78a17e7000-7f78a17e8000 rw-p 00002000 08:02 21724                      /usr/lib/pango/1.6.0/modules/pango-basic-fc.so
7f78a17e8000-7f78a17f1000 r--s 00000000 08:02 50525                      /var/cache/fontconfig/945677eb7aeaf62f1d50efc3fb3ec7d8-x86-64.cache-2
7f78a17f1000-7f78a17f3000 r--s 00000000 08:02 50517                      /var/cache/fontconfig/99e8ed0e538f840c565b6ed5dad60d56-x86-64.cache-2
7f78a17f3000-7f78a17f6000 r--s 00000000 08:02 50516                      /var/cache/fontconfig/e383d7ea5fbe662a33d9b44caf393297-x86-64.cache-2
7f78a17f6000-7f78a17fa000 r--s 00000000Aborted (core dumped)