Grats!
For future reference, if you're in this situation, exceptions can be made if you talk to your faculty head and professors to attend ceremonies. (not about passing the course though)
It really sucks to not be able to graduate with 'your year', and they understand that (well, in engineering at least). You may or may not get your diploma or other awards (whatever accompanies the service) but you can be a part of the fun....
For more information (not directed at you) don't post on MacInsiders, but take this up directly with your faculty head, programme co-ordinator, or the Dean's office itself. However, it must be said that getting to know your professors is a huge boon, because it makes 'mark negotiations' easier...