Popup menus no longer works in clips

I've broken something or got something set and no I can no longer do anything with clips that involve clicking on a clip and using a popup menu.  Every time I right click on a clip I get the windows "ding" sound.  I even get the "ding" when I sometimes click on the timeline.  This used to work (I've used SONAR for years).  Does anyone have any ideas what's going on and what I can do to fix it?
 
Edit: The ding only happens if the mouse is right on tip of the now time vertical line.  Strange as I don't remember this happening before.  Has it always worked this way?  I'm running X3e.

Thanks,
Jim

I tried different projects and rebooting with no change.  Just to clarify (and maybe it's always worked this way, but I didn't think so): if the mouse cursor is over the vertical line marking the now time (the mouse cursor is an arrow), clicking on any mouse button causes a "ding".  If I move the mouse a little left or right, the cursor changes to something else (depending on what tool is selected) and right clicking the mouse brings up the popup menu.
 
So I've got a "work around", which maybe is how it always worked.  But I think something changed recently because I don't recall having to make sure the mouse was a little left or right of the now time.
 
Jim