BT2 worked fine with the generic i810 option number 15 in the xorgconfig. I either get a 104 error or blank screen with the same parameters for X in BT3 that have worked for BT2. I even installed a Intel video driver patch for Slack 12. What's so different about the intel driver support between Slack 11 and 12?
Right now I have full resolution in VESA mode but it's not perfect.