We are running latest version of Opmnager

We are monitoring our SQL 2008 server using the monitor :  Log Files Used Size

Unfortunatly the sizes showed in the Opmanager are wrong.

using the query on sql server I`m getting:

SELECT DB_NAME(database_id) AS DatabaseName,
Name AS Logical_Name,
Physical_Name, (size*8)/1024 SizeMB
FROM sys.master_files
WHERE DB_NAME(database_id) = 'CRV'

crv = 5043MB
crv_log = 379

In Opmanager the size of the Log Files Used Size  is 7399KB

What can be wrong, did I missed some configuration?