No Empty Frequencies?

Today I was listening to my iPod via iTrip when I noticed my signal was getting disturbed. I had my iTrip setup to broadcast on 102.5mhz and I am sure it was free the other day. So I turned off my iPod and as I had figured, there was a station that was interfering with my music. So I started to search for an empty station and there wasn’t any! I don’t know why but I think it has to do with todays weather but every frequency had some kind of interference from a nearby station. Really sucks, its like the iTrips worst nightmare.