Just curious, you said mame32 is in the startup. Is it running when you start game ex? If so, take mame32 out of the starup, and put game ex there instead. Game-ex calls mame32 and if mame is already running, I beleive it simply calls another instance of mame32. This would explain your slowdown. I am a noob at game ex, but I did run into this problem as well, and what I outlined above fixed my issue.