I have some bug with a RadioGroup and a few Radio buttons added to it. It works as expected in FF, but in IE only the first one is rendered. I was planning to write a demo to replicate the bug, but it looks like it replicates in the official GXT demo.
I still see the problem and I have asked others to test it in IE7 on their machines and some of them saw it too. Do you want me to post a screenshot of http://www.extjs.com/examples/pages/forms/forms.html as viewed in my IE?
We had this problem with release 2.1, but you know better what release you are using for your demos.