I recently upgraded the memory in my eMachines T1090 (which uses a Cognac+ 115661 / 20000731 motherboard with a 900mhz Celeron and the 82810 Graphics Controller and runs Windows XP Home & DirectX 9.0c) from 256mb (2 x 128mb memory boards) to 512mb (2 x 256mb memory boards), which is the maximum it will support, according to numerous web sites. Newly installed memory boards are double-sided 256mb Micron PC133U-333-542-A, nonregistered, non-ECC, CL3. After the upgrade, I am getting intermittent loss of video (monitor shows "No signal" and goes black). If I go back to the 256mb configuration, the video runs normally. I have run the "extended test suite" of Microsoft's Windows Memory Diagnostic tool on the new memory overnight, and it shows no memory errors after 11 full passes, so I think the memory is ok. I have tried running both 6.6 (6.13.01.3004) and 6.7 (6.13.01.3196) Intel graphics drivers. Any ideas on what might be causing this problem and how to fix it? TIA for the help.