I've got Celsius R610 with 2GB RAM an year ago and it was working ok till now. Recently I bought another 2x1GB kit and installed it on the system board. When I start the system before BIOS initialization I get a short beep and the workstation starts. In BIOS and in every other OS (win xp prof as an instance) I could see only 2.8GB of the whole RAM. If I try with CPU-Z, Everest or make a test with the Fujitsu-Siemens Diagnostics tool I see all 4Gigs, but can't really address them. On first sight I'd say it's an elementary issue with a broken DIMM, BUT if I try using only one of the both kits (doesn't matter which one) I see exactly 2Gigs in BIOS. The memory is configured correct - 1+2 or 3+4 or all 4. Any ideas?