If you havent knowingly opened more than one mIRC, it could be that your school/work/provider are giving several ppl the same ip, in which case you would need to talk to them. Other possibilities:
-you have a trojan doing it, run a couple good virus scans, including one of the free online ones like housecall at
www.trendmicro.com-someone else within the same ip range has caused a problem and the network has set a wide ban
-not knowing the exact msg, i dont know if your ip is klined, but you would need to talk to the admins at that network to resolve that, check their website
