A few days back, I published the article called "Watch for Shrinking Credit Cards." It talked about how credit card companies can be sneaky and how they should be watched closely. Since then, I had yet another unique experience that furthers this point.
As stated in the article, I used my tax return to payoff one of my credit cards completely. I monitored the account for a few days to make sure there were no pending transactions that would post after the payment was made. For the last few days the account has maintained a $0.00 balance. While managing my other expenses today using Mint, I noticed that there was now a $25.13 finance charge on that credit card account. I went to the site to investigate and found that with my new statement, a pro-rated interest was being charge for the previous balance on the last statement before it was paid. Silly me for thinking that by clicking on the payment button that says "Pay Current Amount" that would bring my account current.
If it wasn't for Mint, I probably would have never seen that charge and it would have gone delinquent causing all kinds of problems. So the morale of the story is even after you pay off a credit card, continue monitoring it for at least a few billing cycles.