Strange bug on initial login

[tyllie]

This bug showed up for me a while back, then went away, and now is back. When I first login all my hotbars will be higher on the screen than normal and my mouse will be off. So in order for me to click on a button or anything else in game, I have to actually click a ways below the actual button. The only way to fix it is to log out completely to desktop and log back in. On the second login, everything is always normal. This happens 100% of the time. I mostly just ignore it, but it is a little annoying. Any ideas how to fix?