Strange Event log error

Hello:

I am running a server with IIS 6 installed on it. I am using Excel 2003
over DCOM to create spreadsheets and stick them into the browser. When a
non-administrator tries to open the spreadsheet, the following error shows in
the event viewer:

Object Open:
Object Server: PlugPlayManager
Object Type: Security
Object Name: PlugPlaySecurityObject
Handle ID: -
Operation ID: {0,171964526}
Process ID: 908
Image File Name: C:\WINDOWS\system32\services.exe
Primary User Name: SERVER$
Primary Domain: DOMAIN
Primary Logon ID: (0x0,0x3E7)
Client User Name: user
Client Domain: DOMAIN
Client Logon ID: (0x0,0xA35F61A)
Accesses: Unknown specific access (bit 0)

Privileges: -

Once this shows up, the user is prompted to log back into the IIS server.

Any ideas?

Thanks in advance...
Brian