Ask HN: Has your Gmail priority inbox been broken since last week?

Last week, starting Thursday morning, my Gmail priority inbox has been marking some spam as priority, and missing some important messages.

When they first launched the product I spent a bunch of time training it, and it's been 99%+ accurate for me ever since.

But starting last Thursday, I keep getting things like Groupon mails and other offers marked as priority, and direct messages to me in response to messages I've sent marked not important.

I was wondering if it was just me or if they changed something last week?