We’ve got a Sharp LC32DA5U in our dorm connected to a homebuilt PC from Frys. Recently we upgraded to Ubuntu Karmic and the latest SVN releases of XBMC. In order to get a reasonable resolution out of the TV/PC combination we needed this little xrandr script to set the resolution before xbmc starts up. The modelines for this TV are not easy to track down, so here they are in script form for future reference.
#!/bin/bash
# This one leaves a vertical stripe on the left
#MODELINE="74.250 1280 1320 1376 1650 720 722 728 750 +HSync +VSync"
# This one seems to actually work
MODELINE="74.250 1280 1390 1430 1650 720 725 730 750 +HSync +VSync"
xrandr --newmode 1280x720 $MODELINE
xrandr --addmode DVI1 1280x720
xrandr --output DVI1 --mode 1280x720