1. drive works fine on other computer
2. i change my previous drive because of that error (nec ad-7170), but that drive works fine on another pc..
3. yes, only 4 (that was "repaired" )
4. I've got ""Western Digital 320GB 7200rpm 16MB cache SATAII [3200AAKS]""
tomorrow I'll try another HDD
and last. i can sometimes burn a dvd, when i disable all applications that use HDD (utorrent, AIM, anti-virus, and LAN connection)