Hi Jon:
I do have the develop icon on my toolbar. I just don't think to empty cache when something goes wrong. I will do that and restart the next time it happens.. Thanks.
The best that I can do is to suggest that you empty the Safari cache. If you don't have the Develop menu enabled (Safari > Preferences > Advanced), you can use the keyboard shortcut: Command-Option-E.
Relaunch Safari and see if that helps. This is a stab in the dark, but it won't hurt anything. Be aware, however, that you will temporarily lose site-specific icons. They will regenerate as you navigate to those sites.