I am in my first steps with the N800..I´ve got a Sandisk 2gb card, and inserted it on external slot on the N800, transferred some music, pictures, etc...so far, all ok. But today, I was transferring some videos after converted them with Videoconvert and an error appears in the middle of the transferring process on xp. Then, the whole content of my SD card was erased, and the SD card is no more available on the N800 (grey color)...any suggestion? Is my card going straight to the garbage or there is some way to get it back to life? XP shows that "no card is present" (despite it see the card inserted in the N800 as F drive)..no chance to format it (neither xp or Panasonic SD formatting tool). When I try to format it, "no media present, please insert a card".
I think it is a real concerning issue.

same happened to me using old os2007 version. new firmware seems to have solved it.

When doing video convert, i write onto pc and later copy video to n800 that has card. Seems less dangerous. video writing may try to write faster that n800 can take it if you try it in one step. Just a guess....

I sent memory back to manufacturer, Transflash, and thew sent a new one. So think twice before you throw it out.