Got an Intel Core Duo here (17") with MacosX 10.4.5.
The mighty mouse does not respond to right-clicks, but I have choosen to let it behave to use primary/secondary buttons. Also, the system profiler says it's indeed the Mighty Mouse (Mitsumi thingie).
Also, sometimes when I click on the desktop I suddenly am drawing a selection box (normally you would leftclick and hold the left mouse button on the desktop and it draws the "selection square"). But now, when I release the left mouse button, it keeps drawing the selection square, even when no button is being pressed!
Also normally, when you click on the top-menu (e.g "File") it shown the menu contents, when I move the mouse to the right (e.g to "Help") it auto-opens that menu. But with the mighty mouse, I have to deselect the topmenu and select "help"...and so forth with every menu.
Is this a known software/hardware related error?