How could the op say he "was actually doing fine paying everything on time" when he / she had to file for bankruptcy? Obviously they were not doing fine. This comment alone shows that the OP does not understand living within ones means.

I would assume that some of the CC companies had to write off some of the debt. As others have reported, the banks have a VERY long memory and will refuse credit for many years past the 7 that show up on a credit report.