Re-update didn't work. Disabling all other plugins didn't work.
Trying a fresh clean install in the next days.
Tried with fresh install of srcds, Metamod:Source and SourceMod, still doesn't work.
Now testing with snapshots. => Also failed.
Now looking into sourcecode and found this:
http://hg.alliedmods.net/sourcemod-c...mn_console.cpp
Maybe this is because line 888 is still @1024 bytes?