Active Desktop Sites won't display

[JohnGalt]

Hi,
I have 2 maps on my desktop that sync every 1/2 hour.
Its worked fine for about 2 months. Now they won't display, nor will any other site (as an active desktop item).

They _do_ display when I boot up. But when they sync or I hit Refresh, I just get the X's.

I'm running IE5.5 with Win2000 pro. I've cleaned out my TIFs.
Funny thing is that this same problem happened when I was running IE4 with Win95 on a different PC.

Any Ideas?

Thanks,
Tom