ah HA!!!!!!!!!!! Do your messages look like this?
Wireless system with MAC address 001CF06E435D disconnected for reason: Received Deauthentication
Wireless system with MAC address 001CF06E435D associated
Wireless system with MAC address 001CF06E435D secured and linked
(please say yes)
Yes Clancy I see those messages almost immediately after the "Wireless restarted" messages (and sometimes just before as well).
Yes I do use MAC address filtering but see no need for IP reservation (it always gets the same address anyway since there are multiple connects before the lease expires, and I only have a total of three devices attached (2 wired, one not).
Based on your edit and the pattern I observe, it appears to be a normal phenomenon - perhaps the "green" feature of the router where it turns off interfaces/ports if not in use?