Originally Posted by
Dex
Pretty sure that's expected behavior, whether in IE, Firefox, or Safari.
Your scroll-wheel is going to scroll through whatever window the cursor is localized over, and now since it sees the sigs as separate windows within the browser, it will scroll all the way through that window before it continues to scroll through the main page.
The best way to avoid this is to keep your cursor on the sides of the screen while you scroll (such as over the Member Info column), so that they aren't passing over the signature areas.