Since 2.9rc10 on rb500: after 5 minutes work disconnect. Aftrer reboot works fine but only 2-5 minutes. tested versions 2.9rc10 2.9 and 2.9.1. on 2.9rc9 works fine.
two rb500 configured to nstreme2 with cards atheros 5213 without compression. standard config with nstreme (5ghz non turbo) with bridge eth0-nstreme0.