Resolving "Key not valid for use in specified state" Error When Importing Registered Servers In SSMS

I love SQL Server Management Studio (SSMS). Is it the best tool out there? Debatable. But when you add SSMS Tools Pack and SQL Sentry Plan Explorer it's pretty hard to beat IMO. It's also usually pretty stable and reliable for me and since I spend most of my day with it open I can't complain. ...but then I re-imaged my work box.
It was time to upgrade to the latest OS and Visual Studio editions at work so why not start over clean, right? Right.
After backing up everything I needed I was off and running and re-loading all my beloved tools when it came time to import my old registered servers list. I thought I was clever; I backed it up "with login and password info" to make life easier. All was well until I imported the file and got the dreaded error message: "Key not valid for use in specified state"
Oh. No.

Of course, the servers then showed up but on closing and re-opening SSMS (2008 R2) my registered server list was blank. CRAP!

Luckily I knew where this info was stored and I navigated to %appdata%\Microsoft\Microsoft SQL Server\100\Tools\Shell\RegSrvr.xml
Upon opening the file in Notepad++ I jumped found the servers that had been setup with SQL Logins and started modifying...

1. I removed the encrypted password and uid=xxx bits from the "ConnectionStringWithEncryptedPassword" element.
2. I added "trusted_connection=true;" to the connection string modified in step 1
3. I changed "PersistLoginNameAndPassword" to "PersistLoginName" in the "CredentialPersistenceType" element.
4. I saved the file and crossed my fingers...

Success! I opened SSMS and had no error. My registered server list was intact and all was right with the world. Of course, the login info for a few servers will need to be corrected, but that's much less work than re-registering a pile of servers.

I hope this info will help others in the same boat :)

-A