I had this same problem on my first '89 Montero. I put up with it for about a year and then the hazard switch stopped working. This caused problems for my turn signals as well. I replaced the hazard switch with a brand new one from the Mitsu dealer. Once I did this, the turn signals and hazard were fixed and I never had a problem with the cruise shutting off with the turn signals.

It's not a cheap fix, though. I think I remember paying around $60 for the hazard switch since it is more than a switch...

Pmontero

P.S. - Hey Eddy, how's Ole Yeller running? I haven't seen it cruising around Atlanta lately...