I read this link yesterday (though now it has gone)
It was in french but did indeed talk of the guid changing on install, NS update, patch etc, so was the closest to Brick's issue I have seen.
I have to admit, Brick, that if you are in fact a cheater/hacker you are by far the most persistent in protesting your innocence i have seen. I am stunningly sceptical in general and when we first looked you up at GQ I was convinced you were dirty but you have got me half convinced of your innocence. That is after you being reported by a player I have known for years and been in clans with (anyone can be wrong from time to time and we have no SS proof)
EA aint gonna help you though I fear.
Your final recourse - buy a new 2142 DVD, start a new soldier, play (clean :) ) with that.