You can also try going to display properties, setting, advance, display, and set you LCD/dvi at primary and turn off all other display after you turn them on and set them as secondary, restart, this seem to work for my ati 8500 with the dell 2001fp. Same for the 9800pro.
You can also work around this with drivers, try installing another driver, perhap try the omega drivers, it seem to work for some..,