I've installed debugging packages of epiphany and xulrunner, started the
program with GDB and this is the output.
I'm on 

Distribution: Debian lenny/sid
Gnome Release: 2.22.3 2008-06-30 (Debian)
BugBuddy Version: 2.22.0
System: Linux 2.6.25-2-686

and I report the same bug here http://bugzilla.gnome.org/show_bug.cgi?id=542818
Tell me if you want more information.

(gdb) run
Starting program: /usr/bin/epiphany-browser 
[Thread debugging using libthread_db enabled]
[New Thread 0xb6b35720 (LWP 7160)]
[New Thread 0xb5a75b90 (LWP 7166)]
[New Thread 0xab7f8b90 (LWP 7167)]
[Thread 0xab7f8b90 (LWP 7167) exited]
[New Thread 0xaaff7b90 (LWP 7168)]
[Thread 0xaaff7b90 (LWP 7168) exited]
[New Thread 0xaaff7b90 (LWP 7169)]
[New Thread 0xab7f8b90 (LWP 7170)]
[New Thread 0xaa7f6b90 (LWP 7171)]
[New Thread 0xa9f16b90 (LWP 7172)]
[New Thread 0xa9715b90 (LWP 7173)]
[New Thread 0xa8f0bb90 (LWP 7174)]
[New Thread 0xa870ab90 (LWP 7175)]
[Thread 0xa870ab90 (LWP 7175) exited]
GCJ PLUGIN: thread 0x81cc6a8: NP_GetMIMEDescription
GCJ PLUGIN: thread 0x81cc6a8: NP_GetMIMEDescription return
GCJ PLUGIN: thread 0x81cc6a8: NP_GetValue
GCJ PLUGIN: thread 0x81cc6a8: NP_GetValue: returning plugin name.
GCJ PLUGIN: thread 0x81cc6a8: NP_GetValue return
GCJ PLUGIN: thread 0x81cc6a8: NP_GetValue
GCJ PLUGIN: thread 0x81cc6a8: NP_GetValue: returning plugin description.
GCJ PLUGIN: thread 0x81cc6a8: NP_GetValue return
** Message: GetValue variable 1 (1)
** Message: GetValue variable 2 (2)
** Message: GetValue variable 1 (1)
** Message: GetValue variable 2 (2)
** Message: GetValue variable 1 (1)
** Message: GetValue variable 2 (2)
** Message: GetValue variable 1 (1)
** Message: GetValue variable 2 (2)
** Message: GetValue variable 1 (1)
** Message: GetValue variable 2 (2)
GCJ PLUGIN: thread 0x81cc6a8: NP_GetMIMEDescription
GCJ PLUGIN: thread 0x81cc6a8: NP_GetMIMEDescription return
GCJ PLUGIN: thread 0x81cc6a8: NP_GetValue
GCJ PLUGIN: thread 0x81cc6a8: NP_GetValue: returning plugin name.
GCJ PLUGIN: thread 0x81cc6a8: NP_GetValue return
GCJ PLUGIN: thread 0x81cc6a8: NP_GetValue
GCJ PLUGIN: thread 0x81cc6a8: NP_GetValue: returning plugin description.
GCJ PLUGIN: thread 0x81cc6a8: NP_GetValue return
** Message: GetValue variable 1 (1)
** Message: GetValue variable 2 (2)
** Message: GetValue variable 1 (1)
** Message: GetValue variable 2 (2)
** Message: GetValue variable 1 (1)
** Message: GetValue variable 2 (2)
** Message: GetValue variable 1 (1)
** Message: GetValue variable 2 (2)
** Message: GetValue variable 1 (1)
** Message: GetValue variable 2 (2)
[New Thread 0xa870ab90 (LWP 7185)]

Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0xb6b35720 (LWP 7160)]
cairo_draw_with_xlib (cr=0x8d72fd0, callback=0xb66731a0 <NativeRendering>, 
    closure=0xbff08940, dpy=0x0, width=468, height=385, 
    is_opaque=CAIRO_XLIB_DRAWING_TRANSPARENT, capabilities=27, result=0x0)
    at cairo-xlib-utils.c:329
329     cairo-xlib-utils.c: No such file or directory.
        in cairo-xlib-utils.c