Anyone else having a problem with Firefox 3 for Mac having multiple fields at once 'focused', making it impossible to copy/clear/type new data into the contents of the field?

I make extensive use of the CMD+F (find within page), CMD+L (location bar) and CMD+K (web search) shortcuts in Firefox. But since the release of Firefox 3.0 for Mac, Firefox frequently gets confused about which field should be 'focused' (the field that is active at the time.)

Right now, for example, my location bar is focused as well as the search field. Typing CMD+K highlights the contents of the field selects all the text in the field as you'd expect, but typing something new into the field doesn't actually enter any data. You have to mouse up to the field and click on it, which defeats the purpose of having keyboard shortcuts in the first place.

Here's a screenshot of the problem in action — both the location bar and the web search field are focused/active, so typing a value doesn't have any result unless I actually click in one of the fields.

It's driving me barmy, and, even worse, I can't find any mention of it from other users on the web. Perhaps I'm searching for the wrong keywords, or perhaps nobody uses keyboard shortcuts in Firefox for Mac as much as I do.

I will say one thing though: quitting Firefox and restarting it fixes the problem for a little while. After some hours of use, it comes back again. I haven't been able to pin down the variables involved with it happening — whether it's a certain number of browser tabs open, multiple browser windows, or what.