I didn't need to recreate my sig, except for the fact that I changed my remote linking site since June. I can do the edit on the sig, just fine, but then when I hit the submit button nothing happens -- can't preview either. No problem with regular posting thus far.
Edit: OK, you'll notice I now have the pics back in my sig -- I did the unthinkable and opened MSIE to see whether I could do the edit there, and it was fine. So, no need to worry about this for now.
It seems that whatever is going on with editing a signature is about the interaction of the forums software and my browser software (Opera). That interaction isn't the smoothest anyway, but is usually not enough of a problem to stress out over (or to use a M$ product).
Still, at some point, when the fundamental restoration has been accomplished, and folks have remembered how to breathe, it might be useful to have a look at that interaction. I use other forums (for instance the Opera forums!) that use vBulletin and I don't have the same display irregularities and grittiness that I experience here. So, it does seem that it's just some setting somewhere that would fix it. Not an issue for now, just a convenient opportunity to flag it.