On the copies of mIRC you don't want to handle irc:// links:
1. Open the mIRC Options
2. Under the "IRC" tree(whatever it's called) select Catcher
3. Uncheck the "Enable support for Chat links.
4. Click Ok (obviously).
On the copy of mIRC you do want to handle irc:// links:
1. Open the mIRC Options
2. Under the "IRC" tree(whatever it's called) select Catcher
3. Check the "Enable support for Chat links.
4. Click Ok (obviously).
That worked for me in 3 copies of mIRC, had some bugs but eventually it worked..