problems with 12.1" DSTN
 

I just tried to install the debian sarge to my HITACHI FLORA310 DL2 LCD PC,but the 12.1" DSTNMonitor (800x600 max)doesn't work well in 800x600 mode in XFree86.

The video adapter(ATI RAGE LT-G 264LT-LG) was recognized automaticly.The monitor displays correctly in 640x480 mode,but in 800x600 mode the bottom of the screen disapears,and there is a 1 inch horizental black band (I guess it is 800-640=160 pixels tall) in the middle.

Then I try to add modeline xx 800 xxx xxx xxx 480 xxx xxx xxx(The xxx can be any number large than 800/480 as i tried,and the HorizSync/VertRefresh can be in any value,they don't affetct) in the Section "monitor",then it works fine in 800x480 mode.

Can anybody tell me how to use 800x600 mode?Thanks.

HITACHI FLORA310 DL2 (PC-5DL02-YD5MA)
PENTIUM MMX 233,64M RAM,ATI Rage3D LT-G (2m ram),12.1"DSTN
XFree86 version 4.2.1.1