Status 1 on Windows server backup - can't open object: Shadow Copy Components

NBU environment:

Master/Media: Windows 2008, NBU 7.6.0.1

Client: Windows 2003, NBU client 6.5

I am seeing the following errors in the backup job detail consistently on the weekly full backup of a Windows Server 2003 client:

4/5/2014 7:50:23 AM - Warning bpbrm(pid=13540) from client bkusolwfl007: WRN - Removable Storage Management: unable to export database (WIN32 21: The device is not ready. )
4/6/2014 11:34:30 PM - Warning bpbrm(pid=13540) from client bkusolwfl007: WRN - can't open object: Shadow Copy Components:\System State\Internet Information Services\IISMETABASE (BEDS 0xE000FED1: A failure occurred querying the Writer status.

The nightly incrementals complete with a status 0. I know it is running an old version of the NBU client, but upgrading it may be problematic. How can I check the writer status?

Thanks!