On my system (winXP on core2duo, calling MAME.) there is something weird with exiting MAME back to AM, it seems to hang for 2 or 3 seconds sometimes before it will accept inputs.
I think the screensaver might be involved, it might activate in background while you are playing a game. Just now when I exited a game I found myself in the AM screensaver, and it wouldn't come out of screensaver when I pressed buttons (it did after about 10s of pressing buttons).
anyone else found this, or got any thoughts?
My screensaver is the default one, showing the snaps, all the options set to No/None.
edit:
I tried disabling the screensaver by setting the timer to 0. And that caused AM not to accept inputs when I exited a game. I could open task manager but when I went back to AM it was still not responding to inputs.