The error occured something like this: The audience cannot be compiled,
because the account used to compile audiences does not have the proper
rights. Change the rights for this account on the Specify Compilation
Schedule page so that it has read and write access to the user profile
database.
Solution: Add/Remove Programs -> WSS -> Detect and Repair Errors
Add/Remove Programs -> Repair Portal Server
Set the Timer Service to use the SharePoint admin account
Central Admin -> reset the Default Access Account
Audiences should now compile fine