[GuyWithNoLife]

If areas of the memory card are going bad, formatting will mark those areas as such and not use them when you format, fixing the issue temporarily... but if you keep having to format to fix a corrupt card, (unless it's a software issue causing corruption) it could be a defective card.

You might not have any issues with it anymore, but you may want to make sure you keep a backup of whatever important stuff you have on the card.

Hope this helps... hopefully after this last format you won't have any more issues.