Poor Network Performance with new NIC in FC3

[Russell66]

I recently replaced an MSI 865G-neo2 -LS mobo that had a failed integrated video with a new ASUS P4P800-E Mobo +Nvidia external (AGP) video. Since that replacement, the networking has always had poor performance; I can DNS / ping anything, but complex sites like google time out, while simple sites such as blagblagblag.org ( my local FC mirror), redhat.com, etc work fine.

The MSI had integrated intel 82562EZ for networking; the ASUS has a marvell 10/100/1000 chipset.
after looking at some of the trials that have been posted on getting the marvell chipset working on FC5, I inserted a intel 10/100/1000MT adapter that I had laying around, but it hasn't helped.

It is possible it is a more general problem as once or twice my MS intellimouse (USB) has locked up, but most of the time it works, whereas the network is always poor.

As my wife is a Windows only kind of person The system is a dual boot, the networking works great from widows.

anyone have any ideas where to start troubleshooting?

Hardware:
Asus P4P800-E Deluxe (865PE)
Celeron 2.4 GHz
512 MB RAM
PNY verto Geforce 6200
intel Pro/1000 MT nic

MS Natural keyboard (USB)
MS Intellimouse 3.0 (USB)

Network:
256 kb/s Qwest DSL with actiontec modem acessed through SMC 10/100 switch; DHCP

History:
Installed FC3 on MSI mobo, there were always some stability issues with the video that exitsted in both windows and FC3, networking always worked great.

replaced old pS/2 keyboard with new MS Natural keyboard- kudzu recognized change and configured appropriately

replaced integrated video and Mobo. kudzu recognized change replaced audio, network and video drivers.
video is currently SVGA rather than Nvidia. poor network performance.

configured yum for FC3-legacy updated all... no performance improvements.

updated sk98lin driver (marvell chipset) from AxelThimms repository, no improvement- network ceased functioning on second boot.

disabled internal NIC in bios, installed intel Pro/1000MT nic; kudzu recognized change, configured

Have tried with and without DHCP, no difference.

Thanks in advance for any help...

[SlowJet]

Nothing apparent jumps out?

Try it without the switch and see if that may be a bottle neck in some way.
9I see no reason to be runing the cable through a switch in such a simple network, a router with a firewall would be meaningfull, but not a switch?)

SJ