It only took one search with the full text of the error to come up with the solution to the problem.
I needed to rework the encryption setup in the SQL Reporting Services Configuration:
Connect to the default instance:
Then, backup, delete, and backup again.
Once I did that process, the error was gone.
We have a few SBS 2K3 R2 Premium installs out there with the number growing.
It is a whole new challenge to get to know SQL 2005! :D
The first source: IPDG3.COM
Which lead to an article on MSDN.
Microsoft Small Business Specialists.