Does the issue still occur if you start Firefox in Safe Mode? https://support.mozilla.com/en-US/kb/Safe+Mode
Sorry for the delay responding (Hurricane Irene!). Installed the latest Firefox version (6.02) and the issue continues. BUT... When I start Firefox in Safe Mode, the issue goes away. I guess that this means that an extension is probably the culprit. In my case this may take a while to isolate where I have quite a few in use. But I can also say that there is no new extensions that can be blamed. Going back and forth between 5.01 and 6.02 makes it disappear/reappear consistently too. I will try to diagnose further as time permits. The recent storm has added lots of work load while placing me further behind too (lack of machine access). So it may take me a while to respond. Thanks, Tim
Good to hear that. You can first focus on extensions that modify the toolbars (add buttons etc) and themes.
Bug is associated with the Speed Dial extension (V 0.9.6.1). For now, I've disabled it. I'm not sure how compatibility issues like these are handled these days with the extension developers. In my case the issue started with FF 6.0 and continues today with 6.0.2. Thanks, Tim
These days, extensions are automatically marked compatible if they do not use features the Firefox developers have changed from version to version. However, some change may be missed and the extension breaks even when marked compatible. Please contact the author of the extension (point him to this bug report). We need his response what his extension is doing and whether something has changed on Firefox side. We can then decide if that was intentional or is some bug the extension uncovers.