MS Document Scanning

I have a problem with MS Office Doucment Scanner. I have both a
network scanner (Canon ImageRunner 3300) and a local HP scanner. For
the Canon I have installed Network Scangear twain Drivers. I can
connect to the Canon thru the Scangear Software and i can see that the
local scanner is installed on my system, but neither one shows up in
the scanner options for MS Office Doc Scanner. However, when i log
into my system as local admin it works fine. Its only the standard
user account that doesn't work.