On one of my guildies pc's with some addons her UI would reset every time, I had to remove these particular addons to stop it doing it.
Win 7 has a restore previous versions option which I've come to love
You just right click the file or folder and select restore previous versions and win will fix it.
If you're on another OS then just unhide files and folders and make a backup of the runes of magic folder in my documents once you have managed to save a ui set up.
The server save will save your locations of skills n such but will not save your addon preferences.
I would recommend just removing a recent addon or one by one till you figure out which one is doing it.
GL
