I tried with 10.0 memstick image and 10.1BETA1 and both installs came to grief when configuring the nfe network interface. (System seemed to hang, power reset needed.)
I have managed by installing without any network and then using bdfconfig.
nfe0: <NVIDIA nForce4 CK804 MCP9 Networking Adapter> port 0xe4c8-0xe4cf mem 0xdffff000-0xdfffffff irq 23 at device 19.0 on pci0
System is a Dell XPS600 made in 2006.
Updated 10.1-BETA and 10.1-RC versioned bugs to 10.1-STABLE.
Is this still an issue? If so, could you please test the 10.2-PRERELEASE images avaiable on the mirrors?