Hi, I have a Dell Inspiron 1564, with this graphics card: Advanced Micro Devices [AMD] nee ATI RV710/M92 [Mobility Radeon HD 4330/4350/4550].
I have upgraded to 13.04 some weeks ago - I do it very cautiously since most of the time the new releases just do not work (I have two linux system partitions, I install the new release on one of them, and keep the old one on the other, and if the new system fails - which is most often the case - then I just switch back to the old system). 13.04 seemed to work after I removed xserver-xorg-video-radeon (see this thread: http://ubuntuforums.org/showthread.php?t=2141224) so I switched to it. But life is not so nice, some programs freeze randomly (firefox, xsane, rekonq, etc) - they do not react to mouse and keyboard events. I can kill and restart them. This is the smaller problem. The bigger problem is that the whole system freezes more and more frequently. Either before or after I log in. This below is part of /var/log/syslog, until the freeze (^@^@^@) Does anyone see problem here?
Quite a lot of my time is spent now on making my notebook work.

Code:
May 13 09:45:15 nbad11 rtkit-daemon[2010]: Successfully made thread 2013 of process 2008 (n/a) owned by '1000' RT at priority 5.
May 13 09:45:15 nbad11 rtkit-daemon[2010]: Supervising 2 threads of 1 processes of 1 users.
May 13 09:45:15 nbad11 rtkit-daemon[2010]: Successfully made thread 2014 of process 2008 (n/a) owned by '1000' RT at priority 5.
May 13 09:45:15 nbad11 rtkit-daemon[2010]: Supervising 3 threads of 1 processes of 1 users.
May 13 09:45:15 nbad11 bluetoothd[972]: Endpoint registered: sender=:1.44 path=/MediaEndpoint/HFPAG
May 13 09:45:15 nbad11 bluetoothd[972]: Endpoint registered: sender=:1.44 path=/MediaEndpoint/HFPHS
May 13 09:45:15 nbad11 bluetoothd[972]: Endpoint registered: sender=:1.44 path=/MediaEndpoint/A2DPSource
May 13 09:45:15 nbad11 bluetoothd[972]: Endpoint registered: sender=:1.44 path=/MediaEndpoint/A2DPSink
May 13 09:45:22 nbad11 kernel: [   54.302288] sd 4:0:0:0: [sdb] Test WP failed, assume Write Enabled
May 13 09:45:22 nbad11 kernel: [   54.305026] sd 4:0:0:0: [sdb] Asking for cache data failed
May 13 09:45:22 nbad11 kernel: [   54.305036] sd 4:0:0:0: [sdb] Assuming drive cache: write through
May 13 09:45:29 nbad11 dhclient: XMT: Info-Request on eth0, interval 34190ms.
May 13 09:45:40 nbad11 NetworkManager[1178]: <warn> (eth0): DHCPv6 request timed out.
May 13 09:45:40 nbad11 NetworkManager[1178]: <info> (eth0): canceled DHCP transaction, DHCP client pid 1469
May 13 09:45:40 nbad11 NetworkManager[1178]: <info> Activation (eth0) Stage 4 of 5 (IPv6 Configure Timeout) scheduled...
May 13 09:45:40 nbad11 NetworkManager[1178]: <info> Activation (eth0) Stage 4 of 5 (IPv6 Configure Timeout) started...
May 13 09:45:40 nbad11 NetworkManager[1178]: <info> Activation (eth0) Stage 4 of 5 (IPv6 Configure Timeout) complete.
May 13 09:46:14 nbad11 kernel: [  105.912018] sd 4:0:0:0: [sdb] Test WP failed, assume Write Enabled
May 13 09:46:14 nbad11 kernel: [  105.914600] sd 4:0:0:0: [sdb] Asking for cache data failed
May 13 09:46:14 nbad11 kernel: [  105.914605] sd 4:0:0:0: [sdb] Assuming drive cache: write through
May 13 09:47:06 nbad11 kernel: [  157.521377] sd 4:0:0:0: [sdb] Test WP failed, assume Write Enabled
May 13 09:47:06 nbad11 kernel: [  157.524076] sd 4:0:0:0: [sdb] Asking for cache data failed
May 13 09:47:06 nbad11 kernel: [  157.524079] sd 4:0:0:0: [sdb] Assuming drive cache: write through
May 13 09:47:39 nbad11 dbus[949]: [system] Activating service name='org.kde.powerdevil.backlighthelper' (using servicehelper)
May 13 09:47:39 nbad11 org.kde.powerdevil.backlighthelper: QDBusConnection: system D-Bus connection created before QCoreApplication. Application may misbehave.
May 13 09:47:39 nbad11 dbus[949]: [system] Successfully activated service 'org.kde.powerdevil.backlighthelper'
May 13 09:47:57 nbad11 kernel: [  209.132872] sd 4:0:0:0: [sdb] Test WP failed, assume Write Enabled
May 13 09:47:57 nbad11 kernel: [  209.135808] sd 4:0:0:0: [sdb] Asking for cache data failed
May 13 09:47:57 nbad11 kernel: [  209.135814] sd 4:0:0:0: [sdb] Assuming drive cache: write through
May 13 09:48:49 nbad11 kernel: [  260.742830] sd 4:0:0:0: [sdb] Test WP failed, assume Write Enabled
May 13 09:48:49 nbad11 kernel: [  260.745766] sd 4:0:0:0: [sdb] Asking for cache data failed
May 13 09:48:49 nbad11 kernel: [  260.745773] sd 4:0:0:0: [sdb] Assuming drive cache: write through
May 13 09:48:54 nbad11 dbus[949]: [system] Activating service name='org.kde.powerdevil.backlighthelper' (using servicehelper)
May 13 09:48:54 nbad11 org.kde.powerdevil.backlighthelper: QDBusConnection: system D-Bus connection created before QCoreApplication. Application may misbehave.
May 13 09:48:54 nbad11 dbus[949]: [system] Successfully activated service 'org.kde.powerdevil.backlighthelper'
^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@
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^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@
^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@May 13 10:21:09 nbad11 kernel: imklog 5.8.11, log source = /proc/kmsg started.