I don't know if this is the problem ... but your code is not const correct
in many places. For example:

Code:
bool sizeSort( const Job & lhs, const Job & rhs){return lhs.getRunTime() < rhs.getRunTime();} //for SJN sort
bool prioritySort( const Job & lhs, const Job & rhs){return lhs.getPriority() < rhs.getPriority();}  //for priority sort