Comment 5 for bug 21569

(In reply to comment #4)
> "You need to run exactly the same command twice, or it doesn't work?"
>
> Yes. I would say that nine times out of ten I get an implementation failure
the first time
> the command is run. I seem to remember this being pointed out on the
linux-wlan mailing list
> (or other documentation - Sorry, I do not remember). It is harmless to run it
a second time
> if it first succeeds.

Sounds fishy. Please send the exact error message.