Actually, I checked it on one of my servers and it is not greyed out, and it is checkmarked (default setting) for full backup.
Here is a link on it: http://www.microsoft.com/technet/pr...prest.mspx
It states that it is for transaction log backups.
I never used this feature, just left it the way it was checkmarked or uncheckmarked.
Kalman Toth - Database, Data Warehouse & Business Intelligence Architect
SQL Server 2005 Training, SSAS, SSIS, SSRS: http://www.sqlusa.com/