Vista and Seven send wrong credentials over a VPN tunnel

[gxcr]

My work samba server is sharing files in 3 scenarios:

1. Serving over LAN (at work), no problem.
2. Serving over OpenVPN tunnel when client is connected at his home LAN (throw a nat-router connected to a broadband modem - ADSL or Cable modem), no problem.
3. Serving over OpenVPN tunnel when client is connected using a mobile broadband modem (Huawei), clients can see the server and shares but can only connect to public ones all the others get a refused connection dialog.

I have isolated the problem: when connecting throw the 3G modem, the username sended to the samba server is the username needed by the ISP to make the mobile broadband connection and not the account username.
I tried with windows firewall enabled, disabled and also with zonealarm, but the problem persists.
All other network protocols work great: tcp, http, ftp, etc.
I have observed that windows always set the openvpn network as a public one. Dialog asking for network location never pop ups.

Please some guidance will have my gratitude. Thanks.

[janjust]

you can force the tap-win32 adapter to be part of the home/work network - open the network connections centre (or whatever it's called and select the tap-win32 adapter. On both Vista and you can change the network type by changing the 'Unidentified network' type to 'Private'.