I have several mIRC clients on my computer, all 6.15. Are they all the latest version? The mIRC.exe name must start with the abbreviation 'mIRC' - so you can't call it 'blahblahscript.exe' it'd have to be 'mircblahblahscript.exe'. This sounds like what you're experiencing from the completely inactivity of the mirc.exe file.
Try reinstalling and make sure you close all other programs when doing so, even the ones in the tray, perhaps the installer was corrupted in some way or an interruption occured (perhaps internally) when installation was taking place. You may also want to make sure the two dirs are in two separate places completely, not sub folders of a main mIRC directory.
Regards,
