MouseMove message interrupted when I change cards

[David Epstein]

Among the controls in a group with background behavior I have a “quick browse” control — a polygon graphic whose many rectangular parts represent cards in the stack.  I handle “mouseEnter” and “mouseMove”, and use the mouseH to calculate which card to go to.
I find that the “mouseMove” message is interrupted when I change cards.  Even though the mouse is moving across what looks like the same graphic, LC seems to treat each card’s representation of that graphic as a separate control.  Thus when a mouseMove causes navigation to a different card, no more mouseMove messages are received, unless I move the mouse out of and back into the control.
Is this how things should work?  Do I need to move my control to a palette so that the change of card that it triggers does not interrupt its own operation?  Are there other options?

David Epstein