Just chiming in with my experience. I have two 7.25 mircs running one with 27 and the other 42 scripts. The first being my personal and the second a channel bot. Both have been running for 3wks 13hrs 12mins and are using 34MB and 64MB respectively.

So I'd have to agree with someone else it's probably a script causing the leak.

My personal site with some scripts I've released.