Arcade monitor + Latest MAME = Slow Down

[8way]

I decided to finally update my cab and with the latest mame(0138) and now some of my games are running at 95-97%. They are still playable but the audio is crap. The thing is i connected a PC monitor to it, and without changing any of the settings in mame, all the game now run perfectly at 100%. The only thing i changed was, I puled out the ArcadeVGA and put in an old video card so i can hook up a regular PC monitor. Then i tried connecting a old SD TV with S-Video, and that worked too at 100% without changing any setting in mame. So only when i have a arcade monitor hooked up i get slower performance. Any info on why this happens.

[isucamper]

are you using directdraw with your arcade monitor and direct3D with your pc monitor? 

either way, you're probably not running in the same resolution in both cases which can account for the difference.  newer mames are definitely slower with some games, like donkey kong in which they switched to full audio emulation which will slow the game down if you don't have a beefy computer