Twitter IM is behaving strangely (2008 May 21, 10am PST)

I'm still receiving updates via IM, but my attempts to post updates or send direct messages have been failing with this error message (via the Psi Jabber Client):

"Remote server not found. A remote server or service specified as part or all of the JID of the intended recipient does not exist."

When I send ON or TRACK, I do get a response, but as much as a minute or two later (when it used to be near instantaneous).

Other people have noticed strange IM behavior also (found via Summize):

@benrasmusen: twitter IM bot is acting all slow and shi.

@kennith: Although twitter IM is offline, but I still can update through it. just i can't get update from the people i follow...

@minim: confused as to why twitter seems to have randomly decided who i get im updates from and who not

@jeremysallen: did twitter im die?

@aDeSe: im twitter is screwed. :( this is always a problem.

As you can see, different people are experiencing im problems in different forms, but those tweets have all come in over the last 15 minutes or so.

I noticed similar behavior just prior to the DB problem that Twitter experienced yesterday, so figured this would be worth a mention.

Edited to add: I also tried deleting my IM account and starting over to see if that would eliminate the weird behavior. I was able to verify without problems, but the strange behavior persisted.