I had a problem with my x1050 since I bought it, 4 months ago.
The problem only occurred only on restricts set of albums. The problem was when I selected any track of one of those albums the X was completed frozen after 5 seconds reproduction. The solution was to click the Home button for some seconds to force the X to reboot. However there was a workaround to avoid this problem, right after of the track selection if I selected the context menu, the back button or whatever menu the X was able to reproduced any tracks. This was a workaround that works fine for me until the last firmware update.
Yes, I said it worked until the last firmware update because now I don’t have any problem with tracks reproduction with any of the “frozen” albums.
And another thing, I did the firmware update because my X suddenly stopped to recognize any touch on the display. It was a very weird situation because it was working and one minute later it stopped to work without any kind of accident, like falling to the floor...
For my experience (for the first problem that I described) I think that Sony fixed some bugs with this new firmware update.
My second problem was dealt with the update, as well. I think that the X was in invalid “internal state” which was reset during the update.