Thanks. It's interesting that you mention the shifting of payment dates. Some of the lates on my installment account actually report on the wrong month and don't match the actual payment history. I've had a horrible time getting it corrected. In any event, I was late in January and the loan company isn't impressed with my requests for goodwill (not that I blame them).
The good news is that my most recent collection (a medical collection also from January of 2009) is about to be deleted and I've just sent in a goodwill letter with proof of enrollment on a student loan that shows 120 days late as recent as September 2008. My current scores are 650, 594 and 584. Maybe in a couple of months I'll get up to 660 and skate through underwriting. 
Earlier this year my scores were in the high 400s, low 500s. It has been a long climb back. I'm looking forward to being a homeowner again. I relocated and had to sell my last home right when the bottom fell out of the market. I took all of my savings to closing and thought I might never own a home again. Now I'm just trying to be patient.
Thanks for all of the responses.
I LOVE your CAN DO attitude!
Hang in there and you WILL own a home again. 
It is possible to get a mortgage with 2 lates in the last 12 months. It all depends on your loan. If you can get a GUS approval then that will help.
I am scheduled to close tomorrow morning on my USDA loan. I have 2 installment lates-09/08 & 12/08. I did receive GUS approval. My middle score is 656.
Keep working on your credit repair and then go meet with a good USDA loan officer.
