Brandon,
We recently discovered this problem as well. We are working on a new build that will include a fix for this issue.
To explain a little (and give you a good work around) here is the problem. TeamLook requires VSTO 2005 SE but will not run on SE Beta due to some changes that were made between SE Beta and SE RTM. Unfortunately, the only way to detect a difference between SE Beta and SE RTM is a registry key that contains the build number of VSTO 2005 SE. Our installer checks this key to verify that a non beta build is installed. Our installer is a 32bit application, and when you are running on Vista x64 with .Net Framework x64, the registry key is put in the 64bit Registry Hive. We incorrectly always check the 32bit registry hive for the value (as by default using the registry functions it is checked) and fail to check the 64bit registry.
The work around is relatively simple. Our installer application is actually a self extracting executable that contains an MSI file as well as the prerequisite checking application. If you extract our .exe using winRar (or any other zip extractor I believe), you can run the .MSI directly and skip all the prerequisite checks. Since you are running on Vista, you will need to make sure that you run the .MSI as an administrator [Right-Click the .MSI and select run as administrator]! If you do not do so, the installer will fail with the inability to write some .NET security settings that are needed to allow the addin to run.
NOTE: Using this work around will skip ALL prerequisite checks and should only be used if this is your exact scenario. There may be unintended consequences which could cause TeamLook to not load properly if you are in other situations.
Let me know if this works for you as well!
Cheers,
~Joe