imagine! bb support being not helpful!
my guess is they told you a couple of things there;
1. dtm 4.1 does not support vista (and vice versa) .... and that;
2. dtm 4.1 is the only dtm reccomended for the 7100i nextel.
are you within these guidelines? if not, what do you have for dtm on your vista pc?
also what type of bluetooth are you trying to pair?