I started having the problems everyone else has described today.
Using Win XP SP3, FF3 (IE at the moment because it sort of works)no changes have been made to my system or settings recently. In addition, my sig pic doesn't show up in posts and in my profile, everything is just red X es instead of buttons-no sig there either but right clicking properties shows its location but states the size as 20X30 pixels.
__________________
|