IntelliSense in Visual Studio 2010 RC freezing-Collection of common programming errors

Sounds like you are using UIA 2.0 (the default on XP and maybe Vista, I think). If possible, can you try upgrading to UIA 3.0?

The problem is that UIA 2.0 doesn’t support virtualization, so the (rather large) completion lists have automation peers created for each item, and the algorithm that does this doesn’t scale very well. UIA 3.0 supports virtualization, so only the list items that are visible have automation peers created.