For the past few days I have been trying to debug a weird IE7 issue with regards to transparent PNGs. Everything on the internet was telling me that what was happing shouldn't happen so this was a pretty frustrating experience. I'm a mac user and use IETester for making sure websites work in IE. It's a solid app and hasn't failed me in the past.

The issue that arose was that all transparent PNGs had a solid white background. My windows system in my virtual machine is rarely used and is XP SP2 with only IE6 installed. That last part turned out to be extremely important. Without IE7 installed, IETester was unable to render the PNGs properly thus creating issues that weren't really there.

As a final test of sanity I downloaded IE7 to see how the site reacted in the real browser and voila...it worked perfectly. After checking IETester again, the white background issue was no longer.

Moral of the story?

If you're using IETester, make sure you have at least IE7 installed.

Hopefully by posting this online, others in the future can seek some guidance if they come across the same issue. Can I have those hours of my life back now please?