read ahead slots

While a stored procedure was running DBCCs against a specific database, the following error was encountered. 'WARNING: No read-ahead slots available...' The SQL Server service hung upon encountering this error and would not respond and the box had to be rebooted. I re-configured the 'RA worker thread' setting from 3 to 8 as a preliminary action. I need you to find out if this setting is 'auto-managed' within SQL Server 7.0, or whether this is something we will need to watch continuously (we had another instance of this failure about 1.5 months ago). Also what else can be done to avoid this problem in the future.