I recently disputed two accounts that were reporting open, but should be closed. I tried to get the creditor to update, my local office was sending in request to corporate(who does the reporting) but corporate wasn't taking care of it.
When those two accounts reported closed my EQ went up 3 points. They were old accounts.
However, know that when you open a new account you will get dinged for inquiry and new account. The new account will lower your average age.