After installing SharePoint Diagnostic Studio 2010 (SPDiag 3.0), you might see three different Timer Jobs failing as you can read on Kirk Evans blog.
The error in the event log is
You do not have permission to run 'SP_TRACE_CREATE'
You do not have permission to run the RECONFIGURE statement
Two options are suggested. Either to disable the jobs or add the farm account to the sysadmin or sqladmin database server role.
As I don’t want to disable the Timer Jobs and also don’t want to give the farm account sysadmin rights, I instead granted the permissions the jobs actually needs and nothing more.
So, my solution is to grant the farm account ‘Alter settings’ and ‘Alter trace’ from the Permissions page under Server Properties.
You also might want to take a look at the Known issues for SPDiag on TechNet.