interface elements shifting horizontally

[Jezek]

I'm having a problem with my UI and have no clue what is causing it. Once in a while when I exit the game and log back in, seemingly at random, several interface elements will be shifted a few centimeters to the right or left. For example, the frames that get moved usually are Zuxana's Model Citizen (player and target portrait models) Bartender 4 (only bars 6-10 for some reason) and Azcastbar (player, target, and mirror bars only)
Anyone have any idea what the problem is?