Should a scanned image under Linux and Windows look similiar?

[Larry Cook]

I am a naive novice when it comes to scanners and images, so maybe this is a 
ridiculous expectation, but I would think that a scanned image under Linux 
would look fairly close to one scanned under Windows, especially when run on 
the exact same hardware.  Both XSane and the Windows software have default 
scan values that are almost identical.  So why aren't the images almost identical?

Here are the two images:

http://www.totalnetnh.net/~lamb/scan_windows.jpg
http://www.totalnetnh.net/~lamb/scan_linux.jpg

The Windows scan is extremely close to the original photo.

I have purposely omitted h/w and s/w specifics because I want to know if I 
have an unreasonable expectation.

Thanks,
Larry