Patrick and Jill Dempsey: Judge Wants Answers ... Are You Really Divorcing???

Patrick and Jill Dempsey have either reconciled or they've been asleep at the wheel in their divorce case, and now the judge has issued an ultimatum ... get on with the divorce or get it thrown out of court.

Jill filed for divorce from her former "Grey's Anatomy" star hubby in January of last year, but since then there's been no action in the case. Patrick didn't even file a response.

Judge Maren Nelson just sent Jill a legal doc, obtained by TMZ, in which she says the case has been stagnant and Jill hasn't moved for a final judgment. The doc goes on to say if the foot-dragging persists, the case could be dismissed.

Here's the real story. As we reported, neither Patrick nor Jill wanted a divorce ... she had problems with the fact that he seemed married to auto racing and was ignoring her and the kids. Patrick responded by saying that he wanted to stay married and promised to drastically cut back on racing, which he has done.