Q: I through the Monster Master ball but no monsters appear. I also don't have any Zombies when I use the Zombie mutator!
A: Go into your Unrealtournament/System directory and look for "Unrealtournament.ini". Open up this file in Notepad and use the "Find" option to find all "bNoMonsters" in the ini file. Make sure they are all set to "False". Just like you can guess, if it says True to any of these, you get no monsters!
Q: How come my monsters aren't attacking people, only me????
A: We are not too certain what is the cause of this, but it seems to be connected to the UT.ini file, just like the problem listed above. It seems the only certain way to get rid of this bug and make your lazy monsters actually do something is to reinstall UT. You might want to look through your UT.ini file and make sure there are no "bNoMonster" options set to true, but if you don't find any, then the reinstall is the only option that seems to work.