What has gone wrong????

[JAZZCNC]

i don't see how it can be the bob as that would not affect the dro's which are running way too fast.

Bob's are sneaky bastards they trick you into thinking they are fine so you go round in circles chasing other things but then you end up back at the BOb and soon has you change them out every thing works fine.!!

Also if you have noise it won't affect the software or the DRO's it will only affect I/O's so causing trips or lost signals. When you say DRO's are running fast what exactly do you mean.?
Mach's DRO's only show the pulses sent out the parallel port so could be that they are sending the correct pulses for the speed but motors/drives are not getting them.? This could be BOB or PP and if you say driver test shows it's fine then BOB would be my first port of call. Thou changing the PP cable is always good place to start.

My first cause of action would be going over all the wiring and connections again with a fine tooth comb. Then trying another PC and PP cable if available or very least re-installing Mach and creating a new XML. Then if no differant go straight for the BOB.

If still no differant After that lot then I'd be concerned and scratching my head.!!