System hangs/crashes after Xorg update

The updates xorg-x11-server-7.4-61.64.1.x86_64.rpm and xorg-x11-Xvnc-7.4.61.64.1.x86_64.rpm forced me to reinstall the ATI Catalyst 10.6 (also tried 10.8).

I get a picture on the xserver and 3d acceleration works, but the system hangs for two minutes now and then.

Logs show:

270.583005] BUG: soft lockup - CPU#0 stuck for 61s! [Xorg:1308]
270.583006] Modules linked in: pppoe pppox ip6t_LOG ipt_MASQUERADE xt_pkttype xt_TCPMSS xt_tcpudp ipt_LOG xt_limit iptable_nat nf_nat af_packet ppp_generic slhc snd_pcm_oss snd_mixer_oss snd_seq snd_seq_device ip6t_REJECT nf_conntrack_ipv6 ip6table_raw xt_NOTRACK ipt_REJECT xt_state iptable_raw iptable_filter ip6table_mangle nf_conntrack_netbios_ns nf_conntrack_ipv4 nf_conntrack nf_defrag_ipv4 ip_tables cpufreq_conservative cpufreq_userspace cpufreq_powersave ip6table_filter powernow_k8 ip6_tables x_tables fuse sha256_generic ansi_cprng krng chainiv rng cryptd crypto_wq aes_x86_64 aes_generic cbc cryptomgr aead pcompress crypto_hash edd dm_crypt crypto_blkcipher crypto_algapi loop dm_mod snd_intel8x0 r8169 snd_ac97_codec ac97_bus amd64_edac_mod snd_pcm snd_timer fglrx(P) k8temp edac_core sg pcspkr snd shpchp forcedeth i2c_nforce2 snd_page_alloc pci_hotplug button ext4 jbd2 crc16 fan processor ide_pci_generic amd74xx ide_core ata_generic pata_amd thermal thermal_sys [last unloaded: preloadtrace]
270.583006] CPU 0:
270.583006] Modules linked in: pppoe pppox ip6t_LOG ipt_MASQUERADE xt_pkttype xt_TCPMSS xt_tcpudp ipt_LOG xt_limit iptable_nat nf_nat af_packet ppp_generic slhc snd_pcm_oss snd_mixer_oss snd_seq snd_seq_device ip6t_REJECT nf_conntrack_ipv6 ip6table_raw xt_NOTRACK ipt_REJECT xt_state iptable_raw iptable_filter ip6table_mangle nf_conntrack_netbios_ns nf_conntrack_ipv4 nf_conntrack nf_defrag_ipv4 ip_tables cpufreq_conservative cpufreq_userspace cpufreq_powersave ip6table_filter powernow_k8 ip6_tables x_tables fuse sha256_generic ansi_cprng krng chainiv rng cryptd crypto_wq aes_x86_64 aes_generic cbc cryptomgr aead pcompress crypto_hash edd dm_crypt crypto_blkcipher crypto_algapi loop dm_mod snd_intel8x0 r8169 snd_ac97_codec ac97_bus amd64_edac_mod snd_pcm snd_timer fglrx(P) k8temp edac_core sg pcspkr snd shpchp forcedeth i2c_nforce2 snd_page_alloc pci_hotplug button ext4 jbd2 crc16 fan processor ide_pci_generic amd74xx ide_core ata_generic pata_amd thermal thermal_sys [last unloaded: preloadtrace]
270.583006] Pid: 1308, comm: Xorg Tainted: P 2.6.31.12-0.2-desktop #1
270.583006] RIP: 0010:<ffffffffa025be74>] <ffffffffa025be74>] _ZN4Asic16Is_WPTR_equ_RPTR19ConditionSuccessfulEv+0x24/0x60 [fglrx]
270.583006] RSP: 0018:ffff8800680a3ba8 EFLAGS: 00000286
270.583006] RAX: ffffc900008fa084 RBX: 00000001000050e5 RCX: 0000000000000000
270.583006] RDX: ffffc9000120f020 RSI: ffffc9000120f020 RDI: ffffc90001bbaba0
270.583006] RBP: ffffffff8100d27e R08: ffffc9000120f840 R09: 0000000000000043
270.583006] R10: ffff88005e111b10 R11: 0000000000003246 R12: ffffffffa0256652
270.583006] R13: ffffc9000120fa10 R14: ffff8800680a3ba8 R15: 0000000100000002
270.583006] FS: 00007f9cb407f6f0(0000) GS:ffff880001c80000(0000) knlGS:0000000000000000
270.583006] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
270.583006] CR2: 00007f9ca6f20000 CR3: 0000000068052000 CR4: 00000000000006f0
270.583006] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
270.583006] DR3: 0000000000000000 DR6: 00000000ffff4ff0 DR7: 0000000000000400
270.583006] Call Trace:
270.583006] <ffffffffa025b17f>] _ZN4Asic9WaitUntil15WaitForCompleteEv+0x1f/0xb0 [fglrx]
270.583006] <ffffffffa0260932>] _ZN8AsicR60016ASICIdleInternalEN4Asic15idle_WaitMethodE+0xa2/0x1e0 [fglrx]
270.583006] <ffffffffa0259b35>] _ZN4Asic7PM4idleENS_15idle_WaitMethodE+0x55/0x90 [fglrx]
270.583006] <ffffffffa0253046>] _ZN15QS_PRIVATE_CORE7PM4idleEN4Asic15idle_WaitMethodE+0x26/0x50 [fglrx]
270.583006] <ffffffffa0240559>] _ZN10QS_PRIVATE11synchronizeEv+0x29/0x30 [fglrx]
270.583006] <ffffffffa0249855>] Z8uCWDDEQCmjjPvjS+0x3d5/0xe00 [fglrx]
270.583006] <ffffffffa0203fd4>] firegl_cmmqs_CWDDE_32+0x334/0x440 [fglrx]
270.583006] <ffffffffa0202a60>] firegl_cmmqs_CWDDE32+0x70/0x100 [fglrx]
270.583006] <ffffffffa01e1f1a>] firegl_ioctl+0x1ea/0x250 [fglrx]
270.583006] <ffffffffa01d6214>] ip_firegl_ioctl+0x24/0x40 [fglrx]
270.583006] <ffffffff8115e4cc>] vfs_ioctl+0x9c/0xd0
270.583006] <ffffffff8115e640>] do_vfs_ioctl+0x90/0x410
270.583006] <ffffffff8115ea59>] sys_ioctl+0x99/0xb0
270.583006] <ffffffff8100c682>] system_call_fastpath+0x16/0x1b
270.583006] <00007f9cb20fe4b7>] 0x7f9cb20fe4b7

What can i do?