My gang started with 6 but has increased to 8. Most of the sessions have had 1 or 2 players absent and their characters left in town to arrange supplies or some such. The party is fighter heavy with 1 thief, 1 mage, 1 cleric, 3 fighters, 1 monk and 1 ranger/cleric. The first couple of sessions went fairly sommthly for the party so I began to tweak things slightly (usually just maxing hit points for the existing monsters). Finally killed a character when he went charging into the chamber of the lizard chieftan and was cut off from support. He nearly killed the chieftan but the last swing by the chief was a crit and down went the dwarf. I think that the player is now switching to another spellcaster, maybe a mage. I have come close on a few encounters before this to killing characters but I generally don't like to do this (unless a player does something stupid) since we only play once a month.