I've connected a sound to the highlight function of mIRC in the form of a simple wav file. This worked with no problems under mIRC 6.03. After the update to mIRC 6.1 I noticed I did get highlighted in channels (color coded) but the sound is no longer played.
I tried to re-attach the sound to the highlight action and tried it out. Unfortunatly this also yielded no results.
Darn it... Someone just mentioned something to me and it turned out to be the problem... Tools > Options > Sounds. The tick in the Enable sounds box was gone... Ticked it on, tested it, and it worked again.