Beta Bug
January 20th, 2013
A bug in a recent beta may cause AdiIRC to crash on startup, if you are affected and cannot updated to a new beta, you can manually go to http://adiirc.com/download.php download the development release, unpack and replace AdiIRC.exe with the one you downloaded and everything should be okay.
Sorry about that, but hey that's whats betas are for :>