Stuck beacon message (interesting update).

[matrix200]

I have recently reported about those on irc (thanks for all the tips by the way).
Anyway today I saw something new and interesting in my logs.
Now I have the following message:
kernel: stray irq7
immediately followed by the
kernel: ath0: stuck beacon; resetting (bmiss count 4)

Now wireless keeps working (I was not at my laptop the moment these errors were logged).
ath0 is in fact using irq 9.
According to dmesg nobody uses irq7 at least there is no mention of it.