I am not sure when it started but for some time now, whenever I right click the properties of "My Documents", it just gives me an error message: "The properties for this item are not available".
Anyway, today I decided to look into this, because I am going to move around "my documents" folder. I found the simple solution in a forum:
Go to Start > Run
Type regsvr32 mydocs
That's it! It worked for me and I can now see the properties of my documents folder properly :)