Mac IE5 problem with hiding/revealing absolute positioned co

I have an absolute positioned hidden span (at 0, that when you move over a button graphic it gets moved and displayed. All works fine on PC IE5+/Nescape7 and Mac Netscape. But on Mac OS 9 IE 5 only partial sections of the span are being rendered upon display, and half of the span is still visible upon hide.

You can see the problem at:

http://software.future-shock.net/DateSelector4/mactest3.htm

It uses display:hide. I have also created another version using visibility:hidden but as I have no Mac, I cannot confirm whether this fixes the problem. I would like a kind Mac user to test this at:

http://software.future-shock.net/DateSelector4/mactest4.htm

If this does not solve the problem then does anybody have any suggestions?

Thanks in advance.