I typically dock toolbars unless it’s intended to be a one time use (infrequent). I have been experiencing a Load Error which I reported earlier and this has not been successfully resolved, so Jim Foltz has hit on the most likely culprit in the situation. Here is a link to my post on that subject:
I remain concerned about this issue despite the responses I recorded in the referenced post because I still have the load errors occurring each time I start SketchUp. I have not been able to apply the advice provided thus far to eliminate the Load Error problem. I guess that some consolation can be taken in the realization that the toolbar issue is related to this and hopefully both issues will be abated by the same solution.