mssql psa problem

[cygnuzz]

Today I try to restore psa backup to my fresh installation of plesk, but the restore process rolled back with no prompt and in the end, error window pop up with "can't restore ms sql database xxx : Value cannot be null, parameter path1" message. I search the knowledgebase, but not found any clue about this kind of error. FYI, I have Plesk installed on Windows 2003 Server SP2 with SQL Server 2005 Standard Edition. Please help me