I have a Nokia E51 and have been experiencing a weird issue.
It seems that my memory card is being wiped totally for some reason. It's done it twice now, and I honestly don't believe that it's something I intentionally triggered.
Just checking on the spec page (http://www.forum.nokia.com/Devices/Device_specifications/E51/) it seems my phone can only handle a max memory card size of 4GB. The card I have is 8GB
Could the card being too large cause the sorts of issues I'm experiencing? Seems unlikely, but it's the best thing I can think of so far.
I haven't done any firmware updates or anything lately. I have however installed some apps via Ovi Suite. These are all to the internal phone memory though.