This bug is related to the following code in isValidPlay().

if(currentType == previousType){
   switch (currentType) {
       case SINGLE:
            valid = compare(previousCombination, currentCombination, 0);
            break;
       case PAIR:
            valid = compare(previousCombination, currentCombination, 1);
            break;
       case THREE_OF_KIND:
       case FULL_HOUSE:
            valid = compare(previousCombination, currentCombination, 2);
            break;
       case FOUR_PLUS_ONE:
            valid = compare(previousCombination, currentCombination, 3);
            break;
       case STRAIGHT_FLUSH:
       case STRAIGHT:
            valid = compare(previousCombination, currentCombination, 4);
            break;
       case FLUSH:
            if (previousCombination.getCardByIndex(0).getSuit() > 
                currentCombination.getCardByIndex(0).getSuit()) {
                     valid = false;
            } else if (previousCombination.getCardByIndex(0).getSuit() < 
                       currentCombination.getCardByIndex(0).getSuit()) {
                                valid = true;
                   } else if (currentCombination.getCardByIndex(4).getValue() > 
                              previousCombination.getCardByIndex(4).getValue()) {
                                    valid = true;
                          } else {
                                    valid = false;
                          }
                    break;
       default:
       valid = false;
}