I took my RT2860 card (which likes to lock up the Soekris 5501 fairly quickly), stuck it in an Openbsd 4.5-current (April 27 snap) and it performed properly and didn't lock up. Mind you, the machine is amd64 and quite well powered. I transferred a lot of files with scp, got about 1.2 MB/s on a single transfer which isn't that bad considering there's about 4-5 access points around or in the building.
The caveat on the ral(4) man page: Some PCI ral adapters seem to strictly require a system supporting PCI 2.2 or greater and will likely not work in systems based on older revi- sions of the PCI specification. Check the board's PCI version before purchasing the card. Does the Soekris net5501-70 support PCI 2.2 or greater? (I couldn't find anything in the specs or docs of it.) That's the only thing I can think of. I can try a new power supply if that's the cause, but it seems so difficult to isolate this bug. Stuart: any luck with your ral* card in your Alix? Regards, Tom