On Yosemite (Mac OS X 10.10.4) I'm not able use the shortcut
<another-letter> works as expected.
I've double checked this in the Keyboard Viewer: pressing
B simultaneously won't show the
B button as pressed.
That is, this is what I see when pressing the 3 buttons:
Same goes by pressing
Command and then clicking the
B in the Keyboard Viewer with the mouse pointer.
Is there any setting that might prevent the
B from getting pressed?