I have had the same problem with Win 7 64. I spoke to Canon Tech Support and after an hour during which we tested various things I was told the the problem was with Windows and I should contact Microsoft. I tried creating a new profile which fixed the problem for about a week, then it came back again! The issue may be associated with Windows Update but I am not sure. On this last go around I created a new profile, then copied in the folders and files from the corrupted profile one at a time to see when the problem would start again. After carefully copying files, backing up, testing Mp Navigator, and if necessary restoring the last good setup I discoved that the following file was causing the problem:
C:\Users<user name>\App Data\Roaming\Microsoft\Windows\Network Shortcuts\My Web Sites on MSN
Note: This file was not present in my new profile. Also, the icon has the shortcut marker on it, but explorer says it is a folder. There is no file extension.
I eventually copied ALL of the other data from the bad profile to the new one and MP Navigator still worked! I then deleted the offending file from the bad profile and MP Navigator started working there too!
I then reconfigured all of my software and started IE etc. for the first time while watching the Network Shortcuts folder. The offending file has not reappeared yet. I made a shortcut to this location so I can keep an eye on it to see when it appears again.
Hopefully someone at CANON or Microsoft will fix this "corrupted" profile issue.
Sincerely,
David Witteried