Sync with iPhoto 11: Events in iTunes not same as in iPhoto 11

I have an event to which I have been merging photos off and on since Sept. 2010. Up to the last time I synced the iPad, that event displayed as a single event in the iTunes list from which I select the photos that I want to sync between iPhoto and the iPad. Now, however, that event appears split in iTunes, even though it is still a single event in iPhotos. Since I have specified to sync all photos, I am now seeing about fifty event with the same name as the single event on the iPad, even though it is a single event in iPhotos.

I have rebuilt my iPhoto library, but that does not seem to help.

Has anybody experienced this problem and solved it? If not, does anybody have suggestions?

Richard