[grasscid]

Hi, I've been running a l4d2 server for some time now, and there's a persistent problem I notice: almost every single client that attempts to join the game gets kicked off "Disconnected by user". The thing is, I never even see these people join the game; they somehow quit out before even loading into the level.
Only a few people actually manage to successfully connect, ever. This is a rather recent problem, too. Only been happening since about a month ago. I used to run the "rage meter" plugin, and it was showing people quitting who hadn't even loaded into the game. This also seems to happen more often on Valve maps; custom campaigns, for the most part, allow clients to connect just fine.
What could be causing this? I'm running several plugins as well as some VPK files that also allow for some extra goodies (Like using melee weapons while incapped.) I have both sv_Consistency and sv_pure set to 0. I can't think of any plugins that would boot players, either.
On top of that, sometimes when the map changes, a human player will leave the game (I don't know if it kicks them off, or if they quit) and the bot they were playing as will disappear from the game, forcing me to open the servers console and sb_add them back into the game. Furthermore, the ported l4d1 campaigns have been having the problem of crashing due to "survivor_mechanic.mdl" not being precached.
I've been considering just reinstalling the server and see if that fixes it. I can't imagine what would cause this :s