How do you highlight a section of code and then sort it? This is only useful for a bunch of variables or the list of functions in a header file. I thought you could highlight a section of code and left click in the left margin or something and a popup would have a sort option. I have changed computers and moved to Windows 7 since I remember doing that.
If you used to use VS2008 or earlier you might be remembering VA's Shift + Right click menu, which included the option to sort the selected lines. This menu is not available in VS2010 and above.
You could map a keyboard shortcut to the command VAssistX.SortSelectedLines or place a toolbar button for this onto your VA toolbar if you wanted easier access.