Really puzzling that it's objecting to apostrophes inconsistently.
I'm pretty certain the same post-parsing routines are used. Or..... I'd better check (tomorrow at the office -- too painful on dialup) to make sure I didn't change post-parsing routines to go with the new posting routine. Which would possibly explain why it doesn't fail in the development environment.
Most importantly, it seems to be handling all the different post-submission scenarios correctly. Public non-reply, public reply, private reply to a public message, all with or without preview. Now if it'd just handle the text itself correctly.