Do mmc cards just die? I think mine did today. I am not able to format it. My external card reader won't even register it.

This happened one day after I installed the updated SDHC kernel, with a few reboots. I'm not saying that it did it - just letting people know what things had changed recently. Nothing else had changed.

So - do they just die - or could the SDHC kernel have anything to do with it?

You're best off asking the kernel author direct - post a comment in his blog. There were some changes made for voltage, probably something you should bring to Philips attention.

Yes, my 1G RSMMC died a month or so ago. Symtom - wild instabiity when swapping on it, stable when not. Think I must have worn down the flash blocks to the point where the wear leveller had nowhere to go. It was over a year old.

This comment from Bugzilla is quite interesting - it suggests that JFFS2 flash is good for about 30 years under normal circumstances.

I know that RS-MMC + vfat is going to behave differently than the internal JFFS2 flash, but I'd be surprised if your card died due to bad blocks unless you were hammering it with continuous updates throughout the period you had it.

More likely it died due to a manufacturing fault (eg. dodgey memory) rather than bad blocks resulting from excessive writes.

I had my gig RS-MMC card die in exactly the way you describe - suddenly, no card readers recognize it (even the 770). After several tests on several readers, still nothing. After a week and a half, I tried it again for some reason and it worked fine. Weird, but it's been fine since.

This just happened to me, on a 16GD Transcend SDHC on my Nokia N800 running the latest 2007.51-3 software. The card is barely 3 months old.