Windows 7: Password Prompt after wake up

Hi Everyone, I have a file server at home that is also a domain controller, and everything works fine until my Windows 7 goes to sleep. After it wakes up, I can no longer connect to the shared files and folders I have setup on the server.

I know the usernames and passwords are correct, but the password prompt just keeps coming back when I try to connect. I can connect via Remote desktop, but I have to reboot my workstation in order to access the shares again. When I reboot also the romaing profile is also not updated because the workstation cannot access the shared profiles folder on the server ...

Can anyone help me on this? I have a pretty complex setup with Windows server 2008 but I am a noob when it comes to network administration.

Thanks in advance.