Thank you for reporting this bug.
How reproducible is this problem? If you run the program from a terminal, is an error message printed?
What version of abrt-gui do you have installed?
Were you trying to report another bug at the time?
Thanks!
Looking at the backtrace, it looks like an assertion failed inside frame 3 of the program's single thread inside _XAllocID whilst using Cairo to draw a GtkButton, using the clearlooks theme.
Reassigning component from "python" to "abrt", but could well be a bug elsewhere.