Glad to hear you got it resolved, sparkling. I would strongly suggest looking at some encryption routine for your sensitive documents on the internal card. I am intending to do something very similar (keep a copy of all CC info, passport, etc), but not without encrypting it! I know you mentioned not being too familiar with Linux, but this seems like something you could manage. It would probably help you sleep at night if you lose it or have to get it repaired.

I've not been looking long enough to see what is available for this platform. On Windows, I use TrueCrypt. There's Linux support for that, but I don't know if Maemo is supported (and I haven't searched). gpgp is likely ported. Given the legal requirements in the UK for hanging over encryption keys, I'd lean more strongly towards TC and its plausible deniability support if you want to extend your storage beyond the mundane...

Another thing to keep in mind is that the chance of your data being fully wiped is pretty slim. Better to store it from day one in an encrypted format. fdisk usually only wipes the filesystem structure, but not any actual data. Add onto that the wear-leveling nature of the memory card, and it's quite likely that every bit is still available (of course, the likelyhood of there being a determined person trying to go after your passport scan is pretty much nil).

Happy hacking