I think one thing that has been a good feature of the BBS is that with a small community, it's easy to feel that we all know each other, and can throw around lighthearted cracks that sometimes appear to newcomers to be actual flames. Said newcomers try to use the same tone, and are surprised when it's not received well.

It's something that I've seen happen in a few communities (IRL and virtual) when they've expanded; some have done better than others at coping with the influx. It depends on a lot of things, including the rate of growth, the willingness of the newbies to lurk and pick up the vibe, the willingness of the established crowd to welcome and educate the new folks - but not limited to just these things, of course.
In short,

• New members - don't be put off by people's flippant styles, but don't expect to "try it on" before you're well-known
• Old members - don't get too wound up by people who don't know the conventions and etiquette around here; take time to gently point them in the right direction (like real-life police, net.police can be either authoritarian or supportive...)