paying off collections can actually hurt your score rather than help, you want to pay for a deletion or (PFD). That way the negative info doesn't follow you, even though you paid it off. You may want to dispute this now.
~~~
Transunion 652 | 3/27/09-677 | 5/20-09 -683
Equifax 4/21/08 -609 | 5/4/08-632 | 12/26-08- 651 | 5/5/09 - 652
Experian 4/16/08- 613 | 11/08 - 646 | 3/27/09-673
~~~