I never had any issues with WPA2, with 10.6 & 10.7
Is this a 2820n?
Which firmware?
as mentioned the 2820vn & 2830n work fine..
Yup it was a 2820n, I don't actually use it any more as had issues with the firmware and VPN connection to work dropping out, I've got a Timecapsule and a Draytek 120 now.