Mutual GNU / Linux

When I try to launch Ryzom client (downloaded from ryzom.com), it crashes at loading screen with segfault.
It works fine with opensource drivers (libgl-mesa-dri and lidgl-mesa-glx), but computer behaves strangely with them and half of installed games don't work with them also.

So, i prefer stay with fglrx, but don't know how to pass through that segfault. There are backtraces from GDB:

32-bit client:

Starting program: /home/konstantin/Games/Ryzom/ryzom_live/ryzom_client
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[New Thread 0xf2f88b40 (LWP 3096)]
[New Thread 0xf25ffb40 (LWP 3097)]
[Thread 0xf25ffb40 (LWP 3097) exited]
[New Thread 0xf25ffb40 (LWP 3098)]
[Thread 0xf25ffb40 (LWP 3098) exited]
[New Thread 0xf25ffb40 (LWP 3099)]
[New Thread 0xed5afb40 (LWP 3100)]
[New Thread 0xeca1fb40 (LWP 3101)]
[New Thread 0xeb148b40 (LWP 3108)]
[New Thread 0xea947b40 (LWP 3119)]

Program received signal SIGSEGV, Segmentation fault.
0x08e35304 in NL3D::CDriverUser::getTotalVideoMemory() const ()
(gdb) bt
Python Exception <class 'gdb.MemoryError'> Cannot access memory at address 0xa44:
#0 0x08e35304 in NL3D::CDriverUser::getTotalVideoMemory() const ()
Cannot access memory at address 0xa44

64-bit client:

Starting program: /home/konstantin/Games/Ryzom/ryzom_live/ryzom_client
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[New Thread 0x7ffff0bc9700 (LWP 3457)]
[New Thread 0x7fffeb9db700 (LWP 3465)]
[Thread 0x7fffeb9db700 (LWP 3465) exited]
[New Thread 0x7fffeb9db700 (LWP 3466)]
[Thread 0x7fffeb9db700 (LWP 3466) exited]
[New Thread 0x7fffeb9db700 (LWP 3467)]
[New Thread 0x7fffe9512700 (LWP 3468)]
[New Thread 0x7fffe8d11700 (LWP 3469)]
[New Thread 0x7fffdfffe700 (LWP 3470)]
[New Thread 0x7fffdf7fd700 (LWP 3495)]

Program received signal SIGSEGV, Segmentation fault.
0x000000000000063b in ?? ()
(gdb) bt
#0 0x000000000000063b in ?? ()
#1 0x00000000026581e0 in FXAA ()
#2 0x00007fffffffdcf0 in ?? ()
#3 0x000000000269b2c0 in ?? ()
#4 0x00007ffff61ee36f in std::basic_string<char, std::char_traits<char>, std::allocator<char> >::~basic_string() ()
from /usr/lib/x86_64-linux-gnu/libstdc++.so.6
#5 0x0000000000a182cf in initMainLoop() ()
#6 0x00000000009c0759 in main ()