Sorry KarlH, but it's purely a numbers game. Although you made the grade last year, they may have recruited enough pilots to fill this year's training slots. Hence the "Thanx but no Thanx". Take solace from the fact they didn't give you the don't darken our door letter, and have asked you to apply again.
DON'T be downhearted, you've obviously got what it takes, now go and do something fun and (legal?) for a few months and have another go next year. Maybe think of doing something to make the Interview Board sit up and think (positively!) about; get involved witha RAF Auxiliary Unit/ATC Gliding School/Travel (there's bags of free seats at the mo!)