Or.. they can just make the signature box so that it's fixed, no matter how long the url or how large the picture.

That will make the url break off to the next line or squish the picture within stretching limits.

I think that's a better solution because everyone wins, sort of. 

Staff should be able to edit posts (and siggys?) that stretch pages temporarily. 

Keeping the original content saved somewhere so nothing is lost, of course, and returning it to the user.

However, at the moment, I am hoping this problem will be fixed by the v3 switch. 

The forums are so unpredictable as to how each user's signature and post formatting will react with others, it isn't possible to make this against the rules. 

Forums in V3 will be different though, and shouldn't have so many issues with stretching. 

Just as broken said. I spend a few minutes yesterday trying to cator to a user's distress that my thread was stretching their page. When I shrunk the image down a bit, they said it actually enlarged and made the stretching worse. I think this has to do with the browser most people use, unfortunately.