OK just thought I'd report back & keep the thread updated.
Only way I can get any functionality is by doing the pin hole reset every couple of hours. Which can't be good to do this consistently.
Am considering getting in touch with Acer & giving them a week to provide a fix or I will be returning the damn thing.
Don't get me wrong before this ICS update I loved my A500 but this experience has seriously harmed my view of android.
I feel that rooting would probably fix the issues BUT why should I be forced to void my warranty due to Acers incompetence.
I will update if I hear anything from Acer (not expecting it though).