Lots of Validate errors ?

Hm, just rejoined the crunching due to the Pentathlon and find I'm getting some ~10% Validate error rate across all my Linux Systems.

Affected Systems are Fedora 8/9/10 x86_64 that run fine on all other projects, no overclocking involved.

All run the default stock application and Einstein was resetted on all systems before resuming crunching.

Odd enough, the only System apparently not affected seems my Vista64 System (at least so far).

What gives? Anyone else seeing this?
(couldn't find anything particularly matching on the front page)