Financial Problems

this is tricky. i thought i was told that at the date of the divorce process/legal separation/etc.....all debt incurred from that point on was individual.  but you're not talking about new debt, you're talking about old debt...incurring late fees, etc.

so yes, sadly, i think you are responsible for this.  i would contact your lawyer and see if you can get your ex to take care of this. meanwhile, you can contact a legit non profit credit counseling firm to seek out help on getting your name off that card (and all others) and explaining the divorce and seeing if you can help your credit.  i would suggest www.debthelper.com

meanwhile, read this:
http://www.divorce360.com/budgeting-and-credit-rating-360.aspx