in my HP NC4400 , BCM 5750 Netxtreme GE networdinterface working.....

do this:

check BCM5750 in windows , make sure "0x14E416FD"

copy attn. file to /System/Library/Extensions

edit /etc/rc file

add:

kextload -t /System/Library/Extensions2/AppleBCM5751Ethernet.kext
ifconfig en1 ether 00:16:d4:46:6a:9c
============
^
this is my mac address, you need change to youeself.