When I went to look at my page via http://ipinfo.info/netrenderer/index.php it looked messed up.

I tried it with http://fetchak.com/ie-css3/ , and it's the same. The background to which the effect is applied is no longer centered, simply placed against the left and top edge.

I then tried in each version of IE via vmware and it displays just fine.

I have tested this on my pc with both PIE and ie-css3 via the above site and both display incorrectly. Disable the htc file and it's centered again.

So is this a bug in pie/ie-css3 or does it have to do with the way ipinfo.net renders the page?

For reference, I t also tried browsershots.org and it displayed just fine.

Stick to browsershots or check out: https://browserlab.adobe.com/index.html

These have been found to be fairly consistent by me. Cheers