Just a heads up to others. There is a kernel regression in the 2.6.35 kernel with regard to, some but not all Intel Gigabit ethernet adapters using the e1000e driver. After an otherwise successful upgrade from fedora 13 to 14, no ethernet connection could be made while using the upgraded 2.6.35 kernel that comes with fedora 14. The 2.6.34 fedora 13 kernels work fine and were fortunately still available after the upgrade.
I have personally seen the identical malfunction on all 2.6.35 kernels I've tried with both Arch and Aptosid and have seen similar reported problems on the Gentoo forum. In each case, going back to a 2.6.34 or upgrading to a 2.6.36 kernel solved the problem so this is almost certainly a kernel issue. My onboard Intel Gigabit ethernet adapter is:
$ lspci -vv | grep Ethernet
00:19.0 Ethernet controller: Intel Corporation 82566DC Gigabit Network Connection (rev 02)
I believe the intel ICH8 chipset motherboards are the ones primarily effected.