I just had the joy of debugging a thorny issue in BizTalk 2010. I spent quite a while wondering why a property schema I had changed was not showing up in the Admin Console with the changes. I even went to the trouble to delete everything from the GAC using gacutil (the BizTalk Assembly Viewer isn't supported on my 64 bit operating system). Still the schema was unchanged.
It finally occurred to me to look at the .CS file corresponding to the problem XSD file. The .CS file had not changed at all, and the attribute on it was read-only. Deleting it from the file system just caused me to get other errors when I compiled.
Then I looked in TFS, and I realized that a co-worker had added the .CS file there. When I deleted the .CS file from TFS, the issue was resolved. Now the schema changes show up in the Admin Console.