Hi - I'm having a similar problem whereby my WHS loses its network connection. I can create the issue repeatedly by starting a manual backup of any of my client PC's running Win 7 Home Premium and Vista Business, it will get to >90% and sometimes even 100% completed and then like clockwork will crash and lose connection. Also, the WHS will randomly lose network connection and the ability to connect to it via WHS Console. I've updated all my NIC and PC drivers, all WHS updates have been installed, and I even bought a new dedicated and expensive switch to connect my entire LAN so as to isolate any issues with the 2Wire AT&T Uverse router. My build is as follows:
AMD Phenom 2 Quad Core 2.8 GHz
MSI 785GM-E51 mATX
4GB Viper DDR3 RAM
4 - Hitachi 2TB SATA II drives
Netgear GA311 PCI Gigabit NIC - used for redundancy and backup.
