iCalendar invites won't send . . . ?

I finally got an iPhone, but it wouldn't sync up to my computer. So, I went to the apple store and they synced it up by doing something rather strange and manually putting my calendars from time machine back on to both my computer and phone (since they deleted my entire calendar trying to sync it!). Now, that it is synced and I can add and delete events anywhere, I am unable to invite anyone to my calendar events. I have no clue how to resolve this.