I installed yesterday on both my Windows XP Pro (1 English, 1 Dutch version) machines a Windows update. I believe that the the update in question was KB840374.
Today i got on both machines the following on connect:
Application Failure mirc.exe 6.1.4.0 in ws2_32.dll 5.1.2600.0 at offset 00008d72
(yes i know, been reported before, but maybe different address, and never solved afaik)
After long experimenting with both mIRC versions 6.12 and 6.14, going back to restore points, uninstalling updates etc. i found out how to solve it:
In the mirc.ini under [options], n2= change the 5th value to "0" and i can connect normal again, no more crashes.
Don't know however what the 5th options actually does.