Aha - could well be.
Mine was a freebie from BT to keep me happy after the failure of three hubs (I wanted the BT voice capability)
Now having said that - my original answer was a bit of a kneejerk assumption perhaps!
Looking at the configuration manager there seems to be the ability to change everything necessary to make any connection really (as long as you have all the details for VPI/VCI and so on.
I reckon it's OK for other ISP's after all - just shows how wrong I can be eh??