Originally Posted by HarryT
I've not found any issues myself with adding a lot of files to the SD card in one go. John fairly clearly has a corrupt file system on his SD card - reformatting should fix that. Copying across as many files as you want shouldn't be an issue - the vital thing is to ALWAYS use the "Safely Remove Hardware" tool before unplugging the Gen3; my suspicion is that this is how many people manage to corrupt their SD cards.
while possible most XP systems are now set to safe mode which prevents this kind of corruption pretty well unless they are removing the card while the light is still flashing (actually performing the write operation). I have done lots of customer support on PDA's using SD cards and have not seen this type of problem. I think the Cybook itself is corrupting the cards in the majority of cases due to the way it is being used. Poor interrupt handling or some other bug in the system that appears when the user does something the machine did not expect and was not programmed to deal with. There are way too many people having problems with this.