ITunes title import error message

Hello,
Not so long ago I upgraded to Windows 7 Pro. It works great, and I haven’t met any problems until now.
But from some reason I am not able to import a downloaded title into iTunes which use to work fine while I was operating on Vista.
Audible Download Manager
The error is this: “Title “Under the Dome (Unabridged) Part 1” has not been added to iTunes.
Please manually import the title file
C:UsersPublicDocumentsAudibleDownloadsUndertheDomeUnabridgePart1_mp332_username.aa into iTunes”

Thank you very much in advance for your suggestions.
