MAME sends monitor out of sync full screen

[mrserv0n]

I have had this mame machine for a year, but all of a sudden when I go to play a game full screen I see the game in 4 quadrants like its duplicating the image and the tracking flickers like crazy, all my other emulators work fine, I can play mame in windowed mode fine but goes crazy when full screened.

Im using a 25" Arcade monitor with soft15hz, but everything is normal as usual accept full screen on mame, I tried reverting to an older mame version that I know used to work and its doing the same thing


thanks