Did the most recent release break authentication for clients using the API?

Since the release tonight, my time tracking client on Mac OS X that I use to post time entries into FA has stopped working. I use Timepost 2.6.4 (http://www.timepost2.com). This was working very recently, and there have been no recent updates to Timepost. I can authenticate fine with the actual web app itself.

Given that tonight's release included OpenID authentication, I wondered if that had any accidental knock-on effects on how clients authenticate with the API. Specifically, I'm being told by Timepost that my login information was rejected, despite it being correct (I've overwritten the credentials with the right ones again just to be sure, but that didn't change anything).

Any ideas? Thanks for a great product, and for consistently rolling out new stuff. Keep up the good work.