I suspect that iTunes 7 is buffering enormous amounts of tune in memory : everytime you come to the end of a track, the whole machine freezes.
Really? Is that on Windows or OS X? iTunes is only using 50MB of memory on my MacBook. Which is actually lower than iTunes 6 did. Some people do seem to be having odd problems with the new release. Not something I've seen here, on either of my machines under OS X.
Paul