Let me describe the setup first:

client PC with several rdp sessions to local servers, all opened from saved rdp sessions with stored passwords, using the standard windows rdp client.

several windows servers on the LAN, with varying server OS: windows server 2003, 2008, and even 2012 now.

When I log onto my PC I open up rdp sessions to all those servers, and keep them open all the time for various reasons. Overnight the client PC is put into sleep or hibernate mode, thereby braking the rdp connections. On the next day when I wake the client PC and login again, the rdp sessions automatically try to reconnect to the servers, and this leads to the question:

starting with server 2008 something apparently changed in the rdp server config, as all servers with 2008, 2008r2 and 2012 will prompt for the password in the rdp session, whereas the 2003 server rdp connections will re-establish without the password prompt. Apparently there is a timeout setting on 2008+ that, when exceeded, requires a reauthentication.

Is there any way to setup the 2008+ servers to behave like 2003 did?

I'd like the rdp sessions to reconnect without a password prompt even after a several hour disconnect.