With the new version, 2.0b3, the control key is not passed as modifier with mouse clicks. This worked OK in the prior version.
Take a look at Emulation in your connection profile. It defaults to using the control key with a mouse click to indicate a right click.
I'm using Chicken 2.0b4 on Mac OS X 10.4.7 to manage Mac OS 9, Mac OS X and Windows XP systems, all using the Default Profile (unmodified).
My Kensington scroll-wheel mouse works fine with WinXP. But neither OS 9 or OS X see the Control key (or Kensington "Right-Click"). So I have no Mac contextual menus. Sigh.
I seem to recall my right mouse button used to work on Mac OS X.
I'd love to know what I can do get Mac contextual menus.