It was a choice of sticking this in here and getting it buried like the other long bug threads, or starting a new thread... but it's nothing compared to the other issues. (Maybe someone already pointed out the following.)
Some people have noticed that the chaingun bullet hit / water effects don't seem to be visible. (page 2
AFAIK, the effects will be missing if you're using unlagged hitscan.
Both g_delagHitscan (server) and cg_delag (client) need to be "1" for you to not see anything (I think "Unlag hitscan" sets both). If you set one or the other by hand, this does not always happen (naturally).
Same for connecting to a server with or without g_delagHitscan 1.