problem with client with vpn - routeros log included

i have a problem with a client. he has a rb133c with a r52… it is connected to an AP with rb512 & SR2.
i use WPA and that client has a vpn with another client. he is having disconnections.
this is the log

what could be the problem?
sometimes i can ping the rb133c but can’t log in with winbox and dude can’t access snmp.

kolorasta -

You have a very poor wireless connection there - see the lost connection and ‘de-auth’ messages…that basically tells me your wireless connection between the two points is having difficulty. The rest of your statements that you can sometimes ping it and sometimes not confirms this as well.

Once you get a solid connection between the two points where you can ping, snmp and winbox in then you should be able to use the VPN provided you set the VPN up correctly…

R/