Bought a samsung syncmaster 997df off of craigslist. At first it wouldn't go past 100hz no matter what (even at 640) switched dvi ports (using a dvi to vga adapter) and now I can set it to 160. I keep getting these random screen tear/skips, no settings seem to fix it no matter what. in any game.. I've synced fps settings in qw/q2/cpm. and tried different settings. They affect it differently but it's still there. Any guesses? is the monitor just dying or something? I can't set any other refresh besides 160 or 85 and lower at 640 either.. ie 120hz won't work on 640.. the monitor just goes black and makes a ticking noise