WPA-PSK with Netgear DG834G

I'm having trouble getting this to work. Here's the situation.

I have an Apple PowerBook G4, with the internal 802.11g (Airport Extreme)
card. I can connect to my Netgear DG834G router with WPA encryption when
the router is set to broadcast the SSID. However, the router seems to
crash overnight with it set up like this so I would like to turn off the
SSID broadcast. When I turn this off, the laptop can no longer connect to
the base-station (it complains that the router doesn't support that type
of encryption). I would like to know if this is a Mac problem, a router
problem, or if I just have some duff hardware. So, has anyone else
managed to get this to work with (Mac + different brand router) or with
(PC + netgear router)?

I have got WEP to work with and without broadcasting the SSID, and it's a
lot more stable without the broadcast.

Hope someone can help!

Ben