Bug in pg_dump in 7.4.6?

I regularly do a pg_dump -s and store the file in CVS. Normally I briefly look
over the diff before committing so I can describe the changes. This latest
time I observed a strange behaviour.

7.4.6 pg_dump seems to be inserting a lot more SET SESSION AUTHORIZATION lines
than previously. Before almost every object even when the owner is the same as
before, whereas previously pg_dump only emitted them when the owner changed.

I'm not exactly sure which version I had generated the previous dump with, but
it was definitely a 7.4.x version. I don't see any changes related to this in
the release notes since the 7.4 release notes.

It's not causing me any problems aside from an overly chatty CVS diff. But I
thought I would mention it in case it was an unintended change.

--
greg