I've has previously been experiencing occasional problems with sending pball related commands to the server. In the past few days I've been playing more and noticing it a lot more.
It seems that the linux client is buffering some commands that are sent to the server. The commands include: all the dropITEM commands, say, say_team, refillco2, camera, scores, tossgren and I'm sure there's plenty of others.
Commands that aren't affected: +attack, +moveup, +movedown, the +strafe commands.
This is most usually experienced when right after I die and try to get into camera view. Or sometimes when I'm typing a lot, it'll queue the messages for about 5 seconds or so.