Watch those late payments!

If you love rewards cards, you'll hate this: Some cards are now erasing your points if you pay late. Here are a few examples.

Discover

If you make two consecutive late payments, you lose all frequent-flyer miles.

American Express Blue and Blue Sky

Beginning in September 2009, cardholders who are late paying their bill lose rewards points earned for that billing cycle. If the account returns to good standing, the points can be reinstated for $29 for each month of points that you want back.

But you would have had to have charged at least $2,000 during that month to make it worth $29.

Citibank

It's adopting a similar practice. If you make a late payment on Citi credit cards that earn ThankYou points, the points you've earned might not be available for redemption until the balance due is paid. There might also be a reinstatement fee for each billing period you're late.

This article appeared in Consumer Reports Shopsmart Magazine.