yup yup, I have itunes match but so often it seems to just go bonkers, I am running with an iPhone4 and maybe that is the problem, but then they should have yanked that feature from my phone if it was going to be crappy like this. That and that podcast app which sucks b*77s.
I recently setup google's music manager and now that it's done uploading all my music I can see that it's a nicer (more reliable for now) player. I ended up using the gMusic app and it all works nicely (there is a instant mix issue that the developer said he is waiting on apple to approve but after that it should be back to nice playback).
I can speak for it being terrible on 4. I just got a 5 and iTunes Match finally became awesome