Safari address bar losing focus

In Safari I do Command-N then Command-L and start typing a URL into the address bar. Depending on the length of what I'm typing, the address bar will lose focus during the process; I must type another Command-L to get the focus back to the address bar.

Is this a bug? Am I doing something wrong? Where is the focus going -- is there some preference I can use to keep the focus in the address bar?

I'm running Safari 6.0.2 on OS X 10.8.2. TIA.