Like everyone else, I've been unable to DCC for over two weeks now. I tried it again after some people reported it fixed last week, still with no joy. I did a little experimenting and found a couple of interesting things. I know it's of little use, since the problem is clearly on BT's end, despite what the support staff keep telling me (I've yet to have someone who will even admit the problem exists), but I thought I'd pass the information on in the hopes that one of the more knowledgeable people here can make sense of it.
After I receive a DCC request I'm still able to send data. I just can't receive any. I can continue talking in a channel and everyone sees my text, but I can't see anything that other people say. I can still disconnect properly, with other people seeing my standard signing off message, but if I leave it connected I'll eventually time out.
While I was testing this I started a second mIRC session to monitor things. This client was, more often than not, able to continue working normally after the first encountered problems. It started exhibiting similar behaviour to the first client on a couple of occasions, but only after several minutes. It was never cut off at the same time as the client which received the DCC request.
Apologies if both of those have been discussed already and I just missed it.