Thank you for taking the time to contact us.
As you may be aware, Internet Explorer on Windows has had support for PNG images since version 4. A drawback in the current implementation has been support for per-pixel alpha values, which in no way detracts from PNG’s value as an alternative to other image formats. Based on feedback such as yours, we have provided a workaround for this issue.
Once again, thanks for providing feedback on Internet Explorer.
-Pablo Fernicola
Lead Program Manager
Yet another Microsoft bug. I still haven't figured out why Microsoft Programs works... they dont validate anything!!!