It's a small bug, the stylesheet attempts to use a color of "#FFFF788;" which isn't legitimate HTML. Colors like this are supposed to use 6 characters, not the 7 used here.

That and firefox complains about using these styles:
SCROLLBAR-BASE-COLOR: {categorybackcolor};
SCROLLBAR-ARROW-COLOR: {categoryfontcolor};

I only point these out because I've had some other trouble with the AVS White theme and I'm attempting to debug it. Y'never know how CSS errors will cascade and cause trouble in entirely unexpected ways.

To see the errors; along with other HTML messages, load the forums in firefox and use the Tools->Error Console menu item.

I found that in a template and have removed the extra F. Should be all set.