Anyway my hoster has finished the "hardware tests" (probably just kept running memtest86 or some vendor CD?) on my CentOS 5.5/64bit machine with quad Opteron 1381 and said that they haven't found any issues. I'll post here a short note if I will experience any issues on my LAPP server (preferans.de - I run phpBB3+ PostgreSQL+my backend for a facebook card game there) Thank you Alex