did you pay any attention to this when it was siad to you
"2) make sure you are running a clean (unscripted copy of 6.2) Try typing /remotes off if you are unsure BEFORE you try and dcc. "
Your complaint sounds like it is a script that fails in 6.2 and causes more than just a dcc problem to appear.
Can you confirm if the problem occrs on a mirc 6.2 with NO scripts loaded (to get to this u can copy the mirc.exe to a new folder and run it from that folder, logining on in it)