1:00.0 VGA compatible controller: ATI Technologies Inc Radeon Mobility X700 (PCIE)

ii  xserver-xorg-core                    2:1.6.4-2                                  ii  xserver-xorg-video-radeon            1:6.12.3-1                                 
ii  libgl1-mesa-dri                      7.6-1

Xorg crashes with such a backtrace:

Program received signal SIGABRT, Aborted.
0x00007fdcfacafd25 in *__GI_raise (sig=<value optimized out>) at ../nptl/sysdeps/unix/sysv/linux/raise.c:64
64      ../nptl/sysdeps/unix/sysv/linux/raise.c: Toks failas ar aplankas neegzistuoja.                     
        in ../nptl/sysdeps/unix/sysv/linux/raise.c                                                         
(gdb) bt
#0  0x00007fdcfacafd25 in *__GI_raise (sig=<value optimized out>) at ../nptl/sysdeps/unix/sysv/linux/raise.c:64
#1  0x00007fdcfacb2de1 in *__GI_abort () at abort.c:88
#2  0x00007fdcfaca8f99 in *__GI___assert_fail (assertion=0x7fdcee613a28 "bo_legacy->is_pending <= bo->cref",
    file=0x7fdcee6139a0 "radeon_bo_legacy.c", line=207, function=0x7fdcee613ae0 "legacy_is_pending") at assert.c:78
#3  0x00007fdcee4619df in legacy_is_pending (bo=<value optimized out>) at radeon_bo_legacy.c:207
#4  0x00007fdcee461ba4 in legacy_track_pending (bom=0x87eee0, debug=0) at radeon_bo_legacy.c:251
#5  0x00007fdcee461f3a in bo_open (bom=0x87eee0, handle=<value optimized out>, size=<value optimized out>, alignment=<value optimized out>,
    domains=<value optimized out>, flags=<value optimized out>) at radeon_bo_legacy.c:448
#6  0x00007fdcee467f1e in _radeon_bo_open (rmesa=0x15f8370, size=32) at ../radeon/radeon_bo_drm.h:110
#7  radeonRefillCurrentDmaRegion (rmesa=0x15f8370, size=32) at radeon_dma.c:196
#8  0x00007fdcee468243 in radeonAllocDmaRegion (rmesa=0x15f8370, pbo=0x15fb050, poffset=0x15fb058, bytes=32,
    alignment=<value optimized out>) at radeon_dma.c:250
#9  0x00007fdcee44b0fb in r300AllocDmaRegions (ctx=0x1661360, arrays=0x1d973c8, prim=0x1d95a44, nr_prims=1, ib=0x0,
    index_bounds_valid=<value optimized out>, min_index=0, max_index=3) at r300_draw.c:529
#10 r300TryDrawPrims (ctx=0x1661360, arrays=0x1d973c8, prim=0x1d95a44, nr_prims=1, ib=0x0, index_bounds_valid=<value optimized out>,
    min_index=0, max_index=3) at r300_draw.c:653
#11 r300DrawPrims (ctx=0x1661360, arrays=0x1d973c8, prim=0x1d95a44, nr_prims=1, ib=0x0, index_bounds_valid=<value optimized out>,
    min_index=0, max_index=3) at r300_draw.c:706
#12 0x00007fdcee508610 in vbo_exec_vtx_flush (exec=0x1d95800, unmap=1 '\1') at vbo/vbo_exec_draw.c:378
#13 0x00007fdcee5046bd in vbo_exec_FlushVertices_internal (ctx=<value optimized out>, unmap=159 '\237') at vbo/vbo_exec_api.c:759
#14 0x00007fdcee504772 in vbo_exec_FlushVertices (ctx=0xb9f, flags=1) at vbo/vbo_exec_api.c:781
#15 0x00007fdcee4d755e in _mesa_set_scissor (ctx=0x1661360, x=310, y=403, width=2, height=1) at main/scissor.c:75
#16 0x00007fdcf9f83446 in __glXDisp_Render (cl=<value optimized out>, pc=0x21c1a8c "\24") at ../../glx/glxcmds.c:1823
#17 0x00007fdcf9f87572 in __glXDispatch (client=0x1460550) at ../../glx/glxext.c:568
#18 0x000000000044d454 in Dispatch () at ../../dix/dispatch.c:456
#19 0x000000000043337a in main (argc=8, argv=0x7fff3ac45d58, envp=<value optimized out>) at ../../dix/main.c:397
(gdb)