For those of you that are using Visual Studio 2005 SP1, you may have run into an issue where typing certain constructs in an XML doc comment (i.e. <![CDATA]> or <!---->) would cause the IDE to become unresponsive.
Below is an example scenario where this behavior can be observed:
To address this issue, we've released a public hotfix that you can download at: https://connect.microsoft.com/VisualStudio/Downloads/DownloadDetails.aspx?DownloadID=9646.
I hope this helps! Please let me know if you have any questions or comments.