black PNG files after update

OS - Windows 2000 Prof, Svc Pack 4
Recent Updates:
Security Update for Windows 2000 (KB917537)
Office 2002/XP Security Update for Office XP (KB914796)
Windows 2000 Windows Malicious Software Removal Tool - July 2006 (KB890830)
Office 2002/XP Security Update for Office XP (KB917150)
Windows 2000 Security Update for Windows 2000 (KB917159)
Windows 2000 Security Update for Windows 2000 (KB914388)

I make images for my websites using MS Image Composer. All has been fine
until the latest Windows updates were installed. For some odd reason images
I save as PNG files are showing up as a solid black image in Internet
Explorer as well as in Windows Explorer (left pane preview). I would assume
that one of the updates changed the way PNG files are viewed in IEXPLORE,
however PNG images made prior to the updates can still be viewed properly.
It is only PNG images made after the updates that are displayed as black
images.

PNG images made both before and after the updates appear fine when inserted
into a Word document or when viewed in a different browser (such as Firefox).
When I insert a PNG file that was created after the updates into a Frontpage
document I can see the image when viewing the normal tab, but when I hit the
preview tab - it displays as a black rectangle again. Back to the normal tab
and all is fine again.

Again, I can still view PNGs made prior to the update without any difficulty
so it seems that the files are now being saved differently - affecting only
the new files. A side by side comparison of properties seems to show that
the files are essentially the same.

Do any of you have any idea why this would be happening and how I might fix
it?

Thank you,
dapps