Internet Explorer 9 Time Out

I have a weird problem here. I have a few internal sites running WC 5.60 on a Win2008 server box. They have been up and running fine, until we started deploying IE9. When trying to hit the sites from a workstation using IE9, nothing happens... the browser status just says "waiting for response from <mysite>". Eventually it will time out. However, this ONLY happens in IE9. I access the same sites using Firefox and Chrome from the same workstation, and they work fine. AND, this ONLY happens using IE9 to access my WC 5.6 sites. I have two sites still using WC 4.xx, and IE9 has NO problem with those.

The wcerrors.txt file shows:

2012.01.8 09:46:01:190 - 4596_3D731F908EE2 - COM Server Timed out - Next line releases - /ShowACat.sdc?cat=ALL - 1413 - 4596 - Com: -1:0:0
2012.01.8 09:46:02:190 - n/a - Forced Release of Server - n/a - 0 - 4596 - Com:
2012.01.8 09:46:04:190 - 6324_C93160B0BD5D - Web Connection Request timed out. - /sdhome.sdc? - 0 - 6324 - Com: 0:3808:6324
2012.01.8 09:46:04:534 - 4596_3D731F908EE2 - RPC Server Unavailable (Invoke): Attempting to Reload Server... - /ShowACat.sdc?cat=ALL - 0 - 4596 - Com: 0:0:6324

Any help would be greatly appreciated!

Thanks,
Kirk Allen