Problem connecting to Windows Vista machine using remote desktop

Question

I have a PC running Windows Vista Business and a Laptop running Windows XP Professional SP3, both connected through a LAN. I can easely connect to the XP machine from the XP machine using remote desktop, but not the other way around. That is, it is impossible to reach the vista machine from the XP machine (or any other machine at the network). I can't even ping it. I've tried to do the following at the Vista machine:

1. I've disabled the windows firewall completely.
2. I've enabled remote desktop connections in the system properties (under this computer -> system properties).
3. I've enabled Network Identification in the Network properties (control panel -> network)
4. I've checked that the computer is found on the network. It's identyfied with both name and ip-number.
5. I've went through all settings in Local Security Principles (under administrative tools) and disabled all firewall settings).
6. I've disabled my antivirus software (panda antivirus) even thoe this should not have any impact.
7. I have no other firewalls running.
8. I've even went as far as stopping the Windows Fireall service.
9. I have rebooted the computer.

Do anyone have a clue why I cant connect to my Vista machine, and perhaps an idea on how I could solve this?

Thanks in advance!