Image in bottom layer not showing up

[ingernet]

Hi folks,

I'm very new to CSS and am wondering if you could help me out.

I've got 2 images: toplayer.png (a transparent PNG, with the middle cut out of it) and bottomlayer.jpg (just a regular old JPG).

The code works fine on IE 5 for Mac OS X (both pictures show up, with the toplayer "masking" the bottomlayer image), but only the toplayer.png image is visible to IE for Windows...and I haven't had a chance to test it on Netscape yet.

You can see it in action (or inaction, as the case may be) at:

http://the.inger.net/test.html

Thanks a bunch!
inger