
I found another bug. Under W7 your tool doesn't allow to edit files if path contains system symbolic link or junction. Here a test with same file but via diferent paths:
C:\Users\Me\1.txt - OK
C:\Documents and Settings\Me\1.txt - ERROR
In second case F4Menu passes to editor just path "C:\Documents and Settings\" instead of full path.
Please note that C:\Documents and Settings is a special junction folder that can't be entered because of access rights, you only can enter its subfolders like "C:\Documents and Settings\Me" (Windows doesn't allow to list contents of "C:\Documents and Settings\" but allows to list contents of its subfolders).