Re: No rounded corners in IE
It certainly wasn't obvious from my previous viewpoint but always so when you find the answer.
I read the FAQ on the z-index issue but this is related to CSS positioning models and backgrounds not appearing at all. Mine appeared fine but just didn't apply the rounded corners. I'm also using a float-based layout.
I did however come across a section mentioning that IE requires the correct content type to be served or it will simply ignore the behaviour:
IE requires that HTC behaviors are served up with a content-type header of "text/x-component", otherwise it will simply ignore the behavior. Many web servers are preconfigured to serve the correct content-type, but others are not.
I tried adding:
AddType text/x-component .htc
to my .htaccess file and it worked a charm. It seems that my web server wasn't one of the pre-configured ones so I just made sure I told it in advance.
I'm glad to see it working, I think it's a nicer solution than using jQuery plugins to simply add CSS effects. I think I'll definitely be a regular user of CSS3Pie.