SQL Server, Local System account, and Event Viwer

I got the following message from SQL Query Analyzer the other day when I was trying to debug a stored procedure on a development system:


Of course, I was unable to debug the stored procedure with the current confiuration. The SP would run, but one could not debug it. The "Event Viwer" (love the spelling) had no additional information, contrary to the message.

INF: Transact-SQL Debugger Limitations and Troubleshooting Tips for SQL Server 2000 and PRB: SQL Server Debugging with Visual Studio Service Pack 5 Requires a Non-System Account both mention a resolution to the problem ("Use the Domain User account (and not the Local System account) as the SQL Server service account and [make sure] that the Domain User account is a member of the Local Administrators group for remote debugging.") but the exact cause is not explained. Perhaps another day...