I have this problem sometimes, about once a month or less depending on usage, but I keep mine on Repeat All. Tends to happen when I get somewhat over-zealous with skipping and also freezes irrespective of how many tracks I've skipped but hits mostly with several clicks. Best I can attribute it to is slight overheating and/or a not quite totally buttoned-up firmware, albeit my guesses are specious at best. Worth noting that I had this problem with my previous logicboard as well.
The inability to skip back on shuffle is just a matter of Creative not adding the code to implement the feature.