gdb: how to get a complete backtrace when fglrx_dri.so segfaults?

I'm experiencing segmentation faults in the fglrx dri library when running my own Qt based OpenGL application. The backtrace I get from gdb (with dbg symbols installed for Qt and my own application):

Thread 1 (Thread 0xb7fd9720 (LWP 1809)):
#0  0x06276705 in ?? () from /usr/lib/fglrx/dri/fglrx_dri.so
#1  0x000020dc in ?? ()
#2  0x000020d9 in ?? ()
#3  0x00000000 in ?? ()

I can not see where from my code I call the fglrx function which causes the segmentation fault. How could I extend this backtrace to see it completely from the main() function down to the fglrx dri library?

edit: To confirm my own application is built with debug symbols:

Reading symbols from /home/user/fglrx crash/crashtest-build-desktop-Qt_4_8_1__Qt-4_8_1__Debug/crashtest...done.
(gdb) br main
Breakpoint 1 at 0x804996d: file ../program/main.cpp, line 21.
(gdb) run
Starting program: /home/user/fglrx crash/crashtest-build-desktop-Qt_4_8_1__Qt-4_8_1__Debug/crashtest  [Thread debugging using libthread_db enabled]

Breakpoint 1, main (argc=1, argv=0xbffff2a4) at ../program/main.cpp:21
21      QApplication a(argc, argv);
(gdb) bt
#0  main (argc=1, argv=0xbffff2a4) at ../program/main.cpp:21
(gdb) n
[New Thread 0xb7d2bb70 (LWP 2475)]
[New Thread 0xb752ab70 (LWP 2476)]
22      QMainWindow w;
(gdb) bt
#0  main (argc=1, argv=0xbffff2a4) at ../program/main.cpp:22
(gdb) s
QFlags<Qt::WindowType>::QFlags (this=0xbffff164) at /usr/local/Trolltech/Qt-4.8.1/include/QtCore/qglobal.h:2284
2284        Q_DECL_CONSTEXPR inline QFlags(Zero = 0) : i(0) {}
(gdb) bt
#0  QFlags<Qt::WindowType>::QFlags (this=0xbffff164) at /usr/local/Trolltech/Qt-4.8.1/include/QtCore/qglobal.h:2284
#1  0x080499a4 in main (argc=1, argv=0xbffff2a4) at ../program/main.cpp:22

You have to generate debug symbols for your own binary as well. Compile your application with GCC's -g option. It's also advisable to turn off optimization for the time of debugging; use GCC's -O0 flag for this purpose.