jandj: There are some other underlying factors that I feel may be contributing a bad image in my part. Mainly the utilization is a bit high between my defaulted credit card (from 2006) that is still on my report, scheduled to drop early 2014, and the current card I have now only having a reasonable credit limit. Unfortunately, I don't believe I'd be able to get approved, but it's always worth a try.
Any idea why the investigation of this account may have made my Experian score drop to 591 from 611?
While in dispute, certain aspects of the debt aren't factored in. 
July 2013 score: EQ FICO 819, TU08 778, EX "806 lender pull 07/26/2013
Goal Score: All Scores 760+, Newest goal 800+
Take the myFICO Fitness Challenge
Current scores after adding $81K in CLs and 2 new cars since July 2013
EQ:809 TU 777 EX 790 Now it's just garden time!
June 2017 update: All scores over 820, just pure gardening now.
Shogun, any chance that the score will go back up at the conclusion of the investigation next week, and the account is removed?
Possibility? Yes, but then again if it was adding to AAoA and will be deleted, then it could go down. But that's not bad either, another baddie gone and your CR cleaner is a good thing. The cleaner the report, the more your score can grow.
July 2013 score: EQ FICO 819, TU08 778, EX "806 lender pull 07/26/2013
Goal Score: All Scores 760+, Newest goal 800+
Take the myFICO Fitness Challenge
Current scores after adding $81K in CLs and 2 new cars since July 2013
EQ:809 TU 777 EX 790 Now it's just garden time!
June 2017 update: All scores over 820, just pure gardening now.