Screen size spontaneously changes upon reboot

I recently purchased a Gateway 507GR with Intel 82915G/GV/910GL Express chipset 6.14.10.3889 and integrated Graphics processor (Intel GMA 900) with 128MB shared video memory out of 1 GB RAM. I set the resolution at 1280X1024 but each time I restrart the computer the resolution has changed to 1024X768. I have a Samsung Syncmaster 760V TFT display which has an optimal resolution of 1280X1024. Gateway tech support says they can't help me since I'm not using a Gateway monitor. Can anyone help me solve this puzzle?

http://www.intel.com/design/graphics/gma90…ay%20Technology

See if they have any FQ's listed and try them for support.