This has happened for a long time. The last update I was able to make to my template was in May. Since then I can't make a change and save at all without getting the error.
I use IE 6 with all of the latest updates. It's all pretty basic.
I wouldn't even mess with the template but apparently there is a possibility that something in my template is causing the text editor to mess up my descriptions when I make a listing. I don't know what that would have to do with things but????
Anyway, I'll try one more time and then file another support case.