Instead of "sleeping" your program you should look into one of the cron-type programs available for Macintosh. One of them is the commercial MacAT another is the shareware Chronograph Or, since your problem is so well defined, you might be able to just whip up some Applescript that'll do it for you.

Of course, when OS X comes out next month, you'll have access to real cron and preemptive multitasking and this won't be a problem at all. :-D

Gary Blackburn
Trained Killer