MENWIZ: yet another character lcd menu wizard library

I am having trouble when using the MW_BOOLEAN. When changing the value, the display updates from OFF to ON in a flicker and goes back to OFF again :~

(I think it worked on MENWIZ 1.0.2.). I have searched the forum and looked at the examples, but found no help. Any of you have an idea of what I am missing?

boolean mashPump = false;        // on-off state for pump
boolean running = false;         // on-off state for BrewCtrl, execute the pid control or only do logging

void setup() {
  Serial.begin(9600);
  _menu *r,*s1,*s2;
  menu.begin(&lcd,20,4);                  //declare lcd object and screen size to menwiz lib
  menu.setBehaviour(MW_MENU_INDEX,false); // turn off the menu index - 1/3 etc
  menu.addUsrNav(navMenu,4);
  r=menu.addMenu(MW_ROOT,NULL,F("BC Main menu"));
    s1=menu.addMenu(MW_VAR,r, F("Set BC On/Off"));
      s1->addVar(MW_BOOLEAN,&running);
    s1=menu.addMenu(MW_VAR,r, F("Set pump On/Off"));
      s1->addVar(MW_BOOLEAN,&mashPump);

The full code is attached to post #358.