So I believe I’ve found the root cause of all of these problems with my K790a. The internal memory is corrupt. It all makes sense now, first the corrupt text message, the random disappearance of all my messages, and then messed up wallpaper. More recently, pictures I’ve taken with the camera have become corrupt and I now get an error that says, “Errors occur in the menu.ml file. This may render the menu unusable.” It is indeed unusable, there are many menus that are no longer accessible; they just don’t show up. I was going to attempt a Master Reset, but I can no longer access any of the menus under Settings.
To top it all off, I lost what text messages I had accumulated from the previous surprise deletion. Oh brother.
I’m going to see if there are any firmware updates available for the device. If that doesn’t solve the problem, Sony Ericsson will be getting a call from me within the week. What started off as a problem with the navigation stick really seems to have snowballed quickly. Anyone else having problems with their K790/K800 or is it just my poor luck?
Update: I see that there are quite a few people who are reaching this page from search engines, presumably with the same problems with the K790/K800 as I’ve been having. Key searches have been errors with the menu.ml file and corrupted files in the phone. I’d like you point you over to this post, where I’ve detailed the fact that I was able to resolve the problem (at least for now) by flashing it with the latest firmware from Sony Ericsson. Hopefully this helps people who were as frustrated as I was.