GMod has been updated to version 55. Here's the changes.
12th February 2009 (55)
Fixed rr_reloadresponsesystems exploit
Fixed +gm_special server crash exploit
Fixed other misc exploits
Fixed water overlay on everyone's screen if RT camera underwater
Server no longer sends Lua files which the client should already have
Fixed redglow1 precache warning
Added hook PrePlayerDraw( ply )
Added hook PostPlayerDraw( ply )
Added player:IsBot()
Added GetHostName() (shared)
Added ServerLog( str )
As always, if you're having trouble with the update try
Cleaning GMod.
Servers will need to be updated before you can join them.[...]
