Oh, yuck, this implies a change to the semantics of the system table or view that maps comments to a table (via the SQL "comment on foo" command.)
This should answer your last question (yes, apparently there are semantic differences beyond timestamp.) I won't worry too much about this - I suspect acs_objects may actually have more than one "comment on" and that 7.2 may not have kept more than one around while 7.3 does, something along those lines. I'll look into it. Sorry we missed this in testing, direct object administration is something that's rarely used since in large installations it's useless.
Yeah, please let Jeff know about the photo-album stuff that breaks for 7.3, we will be officially supporting 7.3 for now on and he'll want to fix it, without doubt.
Probably simple stuff, I'd imagine.
