Using of command "Reset Calendar Cache" depends on the place where user has his mouse pointer in moment of invoking this action.
When you have mouse pointer in the "Calendar window" exactly on the Calendar name row (picture ok.png), it works fine - cache is cleared and TB is restarted.
When you have mouse pointer in the "Calendar window" on the "white background" (picture wrong.png), context menu provides "Reset Calendar Cache" command too,
but calling this action does nothing. It is confusing.