Right. So using WPA is enough, and the rest of the stuff adds no security. That's the only point I was making.

I've enabled "WPA2 and WPA (PSK) (recommended)"
with "TKIP and AES (recommended)" as the encryption

on a US Robotics router

I've entered a nine letter (no other characters...may change later, right now I just want it to work) pass phrase.

On my mac OS 10.2.8, when I try to connect to the network, I'm prompted for a password. I enter it exactly (case sensitive) and I get the unable to join network message.

When I disable the security feature on the router, or simply use the mac address filter, I have no problem getting on or staying on the network.

When I'm prompted for the password on the mac, I notice there is a pulldown menu on the word password allowing me to choose WEP or some other stuff. I dont see WPA or WPA2. Is it possible my g5 doesn't support the WPA encryption?

Please help! Thanks!

Well, it's quite likely that the Airport software in 10.2.8 (Jaguar) doesn't support WPA. That version of OS X is now quite old. You'd do better to upgrade to at least Panther (10.3).
You can usually get a copy of older versions of OS X on eBay quite cheaply. Make sure that you get a retail version of the CD, not just an upgrade or "restore" disk (that came with some particular model of Mac).

Happened to find this. It confirms Panther is required for WPA. If you have Panther, WPA is supported all the way back to the original AirPort card.

Hi All.. If you live in an apartment as I do, then dozens of people are within range of your network… I wan't careful enough when setting up a wireless network last week… it's all very new for me. It looks as if it's been hacked/cracked already, going by the stats from my ISP user page, which shows 60MB or 70MB usage on several days (and that's not believable).
One of the wireless networks nearby is an open network. That's a bit suss I think… or maybe I'm just totally paranoid by this point… totally out of my depth at the moment!

When I first set up the Router I used the security type shown at the top of the list (WEP) but changed to WPA the next day. That is.. WPA2 Personal on the machine connected via Ethernet to the Router (a MacMini) and WPA on the other 2 machines (a G4 and a Ti laptop, both with 3rd party wireless adapters).

At first I blamed the high usage on our kid but she says she's only been using MS Chat and not downloading large images or sound files. But one day our usage was 70MB during 24 hours when she wasn't around. Unfortunately the ISP page doesn't show the exact times, so I can't be totally sure.

Sadly, I didn't change the default Admin password on the Router until a couple of days ago, and then also changed the Network password to a 14 alpha character password. Two days ago (morning) I set the router to exclude all but the MAC addresses of the computers in the network… (afternoon) I changed the Admin password, reset the Network password to over 20 alphanumeric chars and turned off the broadcast of the SSID.

I have a horrible feeling that by doing it in that order, I handed the Hacker (if there is one) all our MAC addresses. Our usage was 9MB today. Only email was checked, and nothing had big attachments.

I've now switched off Airport an all machines and reconnected the MacMini to the ADSL modem (without the Router). The end of our network for the time being. But if the system was being hacked – will it still be hacked even without the wireless connection, or will it be too much trouble for the Hacker do do it another way?

I'm assuming I'll have to a clean system reinstall on all machines, and set it up things again using the kind of things that people have suggested in this thread (really useful , thanks) e.g. turn off dhcp, manually set the IP addresses and filter for those addresses. I'm still not clear about some things though.. should I use the Mac firewall, even though the Router's meant to provide that? Any advice about doing that?

I've been looking at the Router setup pages a fair bit over this week, and I never saw anything that indicated they'd been changed. But I can't think of anything to account for the high bandwidth usage, which only started after the Wireless Network was running, other than a Mac virus or worm. I haven't got any antivirus software running, so I guess no matter what I'll get Norton AntiVirus or similar and use it from now on.

Can anyone recommend an intrusion detection app for Mac? Would a product like Norton Personal firewall offer additional protection? Which logs on the Mac should I be looking at, that might give me other useful information, e.g. how much traffic has been happening via MS Chat? Sigh.

MeredithK