In some cases attempting to edit the XAML files in the Blueprint Edition causes Visual Studio 2008 to crash with the following event log:

.NET Runtime version 2.0.50727.3053 - Fatal Execution Engine Error (7A035E00) (80131506)

The following hotfix should resolve the issue, which is related to the WPF designer:

https://connect.microsoft.com/VisualStudio/Downloads/DownloadDetails.aspx?DownloadID=16827&wa=wsignin1.0