Is the device thats being Deauthed a computer or a gaming console?
I seem to have the same issue, but it is happening on the Wireless connection to my Wii gaming console. Since you specifically asked the question about whether this was occuring to a computer or a gaming console, and this thread went down the "computer" path....is there something I can do to resolve this issue with my Wii? I get this log entry about every 11 minutes:
Wireless system with MAC address 00191DDD?

disconnected for reason: Received Deauthentication.
[

? added for security purposes].
Thanks,
-Rob