virtualbox.org

I have testet virtualbox at a windows 7RC-x64 host. Network I have changed from Default NAT to Bridged network. I installed the guest XP and it works very fast and fine. But at starting up the host takes a very long time, waiting for the login prompt. As I tryed to copy a big file from the Host to a shared network drive at my server, the host system stops unrecoverabel. I need to power it off and on again. After deinstallation of virtualbox everything is working fine.
Host Hardware is an ASUS Intel Bareboon with Onboard Realtec network an Intel Core 2 duo CPU.

There are a few factors that can cause this problem. One is the fact that Windows 7 is still in development, so things can break if you use untested software and drivers. VB uses a driver to access the NIC directly for Bridged mode. If you don't use a VM with bridged mode, you can disable this driver through the interface properties.
Another thing that can be the problem is the Host driver itself for the NIC. There have been reports that the use of Bridged, or the Bridged service driver, on a realtek interface can cause strange behaviour, with this hanging and broken NIC until you reboot or remove VB.