newmom,
What are your immediate credit goals? Do you have a need for new credit lines in the near future? If not it is best to dispute it, as a short term drop on TU will likely not set you back in the long run. Indeed, while you have made great gains, you are still quite aways away from the 640 range that is key for prime loans and cards. You have the ability to get there fairly quickly, but I believe this dispute will help you get there and not set you back too far.