[aiharkness]

It sounds like you have multiple calendars and your default is not what you thought it was, or you've accidently changed it, or it changed with something else you did.

If you have multiple calendars, check and see which one you have been using--i.e. which one has entries and which one(s) are empty. If you have entries in multiple calendars and you did not do it on purpose and do not what the entries spread between calendars, you'll need to move entries to the calendar you want to use as default. See last paragraph below.

Once you decide on which calendar to make default, open options > advanced options > default services, and change both the default CICAL and default CMIME to the one (and email address) you want to use. Do not choose facebook, desktop, or anything other than an email address.

Now open calendar options and in turn highlight each of the calendars that are not the default, and type move, and respond yes that you want to move all entries to the default calendar.

Now try a sync again. If you don't like the action that will be taken if you accept at the prompt, cancel and then re-sync.