I have AMD MP 2 CPU\'s. Yesterday one did run SAH and another CP. After a reboot CP did not start, same thing after three reboots. Ihave ony SAH WU left in machine so I have only 50% running.

Change your general prefences to 1 CPU instead of 2, then restart BOINC. That should fix the problem. When you have an extra WU stored up, you can go back to 2 CPU's.

It's a known bug in BOINC, I encountered it myself - it only happens when a project doesn't have enough WU's to keep a dual CPU (physical or logical) system busy.

Did you shutdown BOINC before your first reboot, Esa? The <a href="http://climateapps2.oucs.ox.ac.uk/cpdnboinc/quick_faq.php#c">FAQ</a> mentions a potential source of model corruption if you didn't. The only way to recover from this is to perform a project update (open the project tab, right click on climateprediction.net and select update from the pop-up menu).
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Thank You for your help. After a re-install of boinc-gui everything went ok. And I did not lost anything... all three hours were safe.