I'm using Windows 7 x64, and extension is successfully associated with files with .txt extension if .txt file type is associated with Notepad (Control Panel\Programs\Default Programs\Set Default Programs).
In that case in description is written that .txt files represent 'Text Document'.
If I associate .txt with Notepad++, in description is written 'TXT File' and shell extension (Context Menu) no longer works.
I'm using [COMServerAssociation(AssociationType.ClassOfExtension, ".txt")] attribute.
In ShellExView program I can see that my shell extension works for ".dic, .exc, .gitattributes, .gitignore, .gitmodules, .log, .scp, .txt, .wtx, txtfile".
Interestingly, even that Context Menu extension doesn't work any more for .txt files (neither for .log), it works for .wtx file type, for instance.
Is there some workaround?
How could I associate shell extension strictly for .txt file types, and not for all txtfile class types.