The CardSpace team blogged about a new "feature" of .net 3.5. You can now work with CardSpace on a windows system that has its system drive formatted with the FAT filesystem... They write: We’ve received a surprising amount of feedback (some of the earliest from Pamela Dingle ) that customers are still using FAT file systems and this is causing problems. I am surprised too. What will be next? CardSpace running on windows95? Help! Sure, the cardstore is still encrypted twice... but still... I believe

After installing .NET3.5: So if you *really* need your cards then make a backup before installing .NET3.5 . The new - polluted - IE7 user agent string: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; .NET CLR 1.1.4322; .NET CLR 2.0.50727; InfoPath.1; .NET CLR 3.0.04324.17; .NET CLR 3.0.04506.648; .NET CLR 3.5.21022) I copied it from the latest xmldap.org relyingparty . It outputs the user agent string to make documenting the interop tests easier. Please notice that this is no-SSL.