Anyone else here have the optional iPod Pioneer headunit from Scion?

If so, do you notice drastic volume differences between songs and/or artists? For example, on most of the music on my iPod, I listen at about 45-50 on the volume...however, some songs are so quiet I have to boost the volume to almost 60 to even them out.

For reference, the radio and cd player play at pretty consistent volumes (i.e. 45 sounds like 45 on both of them), but sometimes when I switch to my iPod, 45 sounds like 30.....

Just curious if I'm the only one experiencing this or not. Thanks!