When people try to put in things that were not in canon when clearly everyone else was told that it should be kept within canon of the game. 

When people don't read the whole Interest check and then join find out what the rp is really about then bail

When people GM then leave for a week or more at a time leaving a confused group of people sitting on their asses without a clue on what's going on.

[i][b]When people just up and leave a roleplay without a single word.[/b][/i]