ReSharper: "Add to abbreviations list" missing

I have a reasonably fresh VS2010 + RS8.1 installation but for some reason the option to add an abbreviation to the abbreviations list is missing :-( So if I AltEnter eg. "ClientID" I would expect to get the option to add "ID" to the abbreviations list (along with the option to rename it to "ClientId" of course). But I don't. Anyone know how to reenable this again? edit: I found out where to maintain the list manually: ReSharper - Options - Code editing - C# - Naming style Thanks in advance