My log is full of these kind of messages.
 
Nov  3 10:58:43 MYDIR655 user.warn kernel: [1030207.450000] SHAN=== Chaning for PS state change for type 0 subtype 208 
What do they mean? 
I have a DIR-655 rev B1 running 2.11 NA firmware. 
I am using Channel 11. Next door neighbor is on Channel 6 and Inssider shows no others.  
I have reserved dhcp IP addresses for 14 wireless devices, although only 2-3 are typically in use at one time.