I've just discovered a security warning that occurs with the latest (Beta 5) version of PIE. Here is how to reproduce it:

1. Create a test.html file and add the following: <a href="https://<your domain>" target="_blank">New Window</a>
2. Replace the url with a valid secure url containing a page that uses PIE.
3. Open test.html in a browser (non-secure url) and click the link in IE (tried 7 and 8). You will get a message that says this page contains both secure and unsecure item.

The test.html file and the page you are calling must be on 2 different domains. It seems to work fine if on the same domain.

If you remove the target="_blank" or paste the test.html URL into a new browser window, you don't get any warnings. For some reason, clicking a link that opens a new secure window to a page containing PIE causes the error. I've been able to reproduce this on multiple domains with different servers.

Has anyone seen this?

I'm having the same problem.

I've tried changing the "url(about:blank)" to "none" as described here: viewtopic.php?f=3&t=128&p=5024&hilit=secure#p5024 and it made no difference.
I've searched the requests in fiddler, and all requests are made over HTTPS.
By removing any CSS classes that call PIE.php I have no problem.
My corners are rounded before the warning comes up.

Any help would be appreciated.

This seems like a fairly big bug and a major drawback to using PIE if your site requires SSL. I'm hoping someone has come up with a solution or the PIE development team is monitoring these forums.

Is this in a specific version of IE or all versions? @atlguy I assume you've tried replacing the about:blank as well with no luck?

I just tried replacing url(about:blank) with none and so far it seems to be working ok. Will have to do further testing.

It's a problem in ie7 and 8 But not 9. I didn't test 6.

I was just able to resolve my issue by replacing "url(about:blank)" with "none" and removing the unused pie.js file from the page. I'm using the .htc file but had the js reference still on the page from when I was testing the javascript implementation of css3pie. By removing the javascript file and replacing the url(about:blank) the issue went away.

Good to hear. Yes, if you include the PIE.js then the logic there will be used and the logic in the .htc will be ignored, not to mention it's twice the download size.