As long as it's been since the late, it may not have been hurting your score. I had the same thing happen. One 30 day from 2004, no increase.
Ficos
3/7/08 TU-646 EQ-640 EX-650
3/17/09 TU-678 EQ 666
3/20/12 TU- 760 EQ 785
Util almost 0 and baddies all gone! now to gardening!