If i were you iw ould go to the remote site console the AP 105 reboot it and log in the cpboot of the AP and start troubleshooting the network connectivity from the same AP to see whats happening....
If it get an ip by dhcp i would issue the command dhcp to get the ip and start pinging the controller to see if it see it alive...
If it has static ip then i would just ping the controller to see it...
If you see it alive then see what happens on the boot process... to see if you get any message in there to see whats wrnog....
IF you say that the VPN is fine and all the networking is fine.... i would do that.
cheers
Carlos