Mach2 resets at random sometimes lists limit switch tripped

Hello, we have been rebuilding a cnc knee mill. This is our 2nd
rebuild. We have everything going but the reset in the Mach2 software
trips at random. Sometimes in 30 mins sometimes in 10 or less. We are
running servos and geckos. We have prox switches on X and Y and micros
on Z. We have short cables, and small cap filters on each. Our debounce
is at 5000. If we go any higher then we blow by our prox switches at
full speed. We can turn the limits off and all will be stable. Z and
its micros are the most stable but our proxes are getting noise. We are
running Windows2000 on a P4 box with gobs of memory. The box also has a
network card installed but we are not using it. We've done and tried
everythiing to get the system solid and stable and this is the last
little pain in the ass we have to over come. I need any and all
suggestions! Thanks