First off, you need to talk to the attorney who represented you in your divorce, if that's what happened. If she was ordered to sign off on the title (i.e. the Quit Claim Deed) and she has not, she could be in contempt of court.
If there was something else in the way of an agreement, then you do need to contact an attorney to give you advice on your next steps.
There was no reason to keep her on the title to "ride out the economic downturn," as being on title does nothing for her. Being on the loan, if that's what you did, only kept her from being able to get other credit. I have no idea why you would have kept her on the deed, and I have no idea why she would not want to give up ownership, either.
Best of luck.... more