It was already reported in the Greenfoot 2.2.0 beta thread (which is, incidentally, where you should post if you are using the beta and have problems - though not for this issue, because, as I said, it's already been reported; it will be fixed for the Greenfoot 2.2.0 release). Remember, it's a beta. You should only use it if you are willing to help test it, report issues, and expect problems!

When is the next release coming? Also its strange that its to do with PlayerData because in the jar files I exported I wasn't actually using PlayerData (I haven't used it at all yet).. I guess just the import alone is enough? Actually now I think of it, would a temporary fix be to change the import greenfoot.*; to an import for all necessary classes in the greenfoot package (just not PlayerData)?

The next release is coming "when it's good and ready" :) Hopefully in the next couple of weeks, but longer if we find more bugs. No, changing import statements won't have any effect. No scenarios can successfully be exported to jar from the 2.2.0-beta, whether they use PlayerData or not.