| >It would be good to describe the status of your card's LEDs
| >when you enable and disable encryption, AS WELL AS GIVING THE OUTPUT
                                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
| >OF 'wiconfig'. Statements like 'stops working' are sufficiently
   ^^^^^^^^^^^^^^^

Emphasis mine.

| Ahh.  Link LED stays on, activity LED flickers, which is what it
| does when the network is working.  "stops working" means it reports
| good signal/noise ratio, good signal strength.  It just can't
| exchange packets with anyone.

Neither send nor receive? What does wiconfig -o show [before and after
the change, please].

| If I turn off encryption on the other machines, and do "wiconfig wi0 -e 0",
| everything talks fine, so I'm pretty much assuming this is just a question
| of the encryption.

OK.

--jhawk