Air France Frequence Plus - Trouble in SFO?

The daily 83/84 SFO-CDG flights switched back to B744 equipment this week, but it seems like there's something wrong. Looking at Flightaware, it seems that 83 got a sub to an A343 on the 27th and didn't operate at all on the 28th. Anyone have any details?

That flight seems to have a lot of "troubles":
http://www.flyertalk.com/forum/air-france-frequence-plus/1322972-sfo-cdg-march-9-a.html