Ok. Well rejected could be if you enter wrong password perhaps ?
But I am sure STA expired is when a wireless client disconnects from the AP, I have noticed that when I do a shutdown of my laptop. As I have wrote before in my firmware bug thread, as long as the system do not crash or hang, what the logs say is not important. As of now, it seems there is a big of a debacle back and forth with some form of authentication issue, as I am running AP1 as "access point", and AP2 as "wireless client". So from time to time the get into a fight, not lasting to long with, de-authentication, and re-authenticaton, a bit strange. But still seems to work fine.
I have only found one serious bug, reload of wlan part firmware fails. Other than that the units seem to work as well as could be expected. The only way to get around bugs, errors etc it so work around it. Thats why I suggested the cable option, if you can do that, always select that option as it is the safest. Running a AP in access point mode, or using is as a wireless client seem that safest bet, as these two have been around since WLAN first came about.
Good luck