thanks for the reply 

i can assure you the hub is not the issue, as i have moved both my trouble some the ants on there own hub, moved the ants onto my PC etc etc, with exactly the same results  these U1's just don't seem to like life.

I have tried them at 0781 up to 0A81 (only briefly at 0A81, just to see if that made a difference), with the same results, its like they just don't want to run 

i guess these 2 could just be dud's