Holy crap, CG! I just noticed that you edited your post to ask me this! I'm sorry!
Yes, your new signature falls under the tv.com TOS. Any of the banners that I post are well within the size limit. You are good to go.
And if you have any kind of photo editing program (even Paint will work) you can open the pics in it and go to "Image" then "image size" to see how big it is, pixels-wise.
I HAVE EDITED THE FAQ TO INCLUDE INFO ON SPOILERS.
don't sweat it--i eventually forgot i posted that, too! and, on a side-note, thanks for letting me use all your stuff. i feel kind of bad, but i still haven't found a photo editing program that my Mac will download and open. (it'll download it, just won't open the file )