I am having troubles with connecting, to anything. All I get when I try to connect to a server is "(22:50:39) * Unable to resolve server". When I try to use sockets, I immediately get "[0] Unknown Error".
If I start another mirc.exe (installed to another directory) it works fine!
Is that application accepted in Firewall? Maybe, you started another mIRC.exe that was in "white list" in firewall. I think so, i don't know other solutions Excuse me for my bad English, I don't speak very well this language :P
If one mIRC connects and one doesn't, it's most likely a firewall issue... even if you think it's turned off. Either that, or the one that's not working is messed up in some way (a script or settings or whatever). Just try to reinstall that one.