2002 S60 frequent alarm triggers

[amkonyk]

I am having trouble with my alarm triggering almost daily and there's nothing I can say is consistent with it. It doesn't matter where it's parked. We've checked all fuses and they seem to be operating. The siren sounds very dull when it sounds but maybe that's the way it's supposed to be. I bought it used in 2004.
Battery has been repolaced about 18 mos ago but this didn't start until about 60-90 days ago.
Any thought before I sink a zillion dollars into taking it to the dealer to try to figure it out?