Still having trouble with my satellite 2800-202 p3-700 384mb. I have a parts box that is the same, after changing shells the other one acted the same, so I don't think it is a physical problem.
After doing a bunch of research and various attempts over the weekend I found some possibilties from different threads.
1) e100 issues in 2.6: I think this issue has been resolved, I also have p3 ghz machine with 512mb. it is also using the e100 driver and runs great so I don't think it is the e100
2) switch ports: have tried multiple switches and different ports no effect.
3) agp aperature size: for some reason the agp aperature is set at 256mb. I have seen some references to this slowing down systems, the laptop has an integrated 8mb savage video card. I can not change it in the bios, any ideas about it?
4) laptop issue, is there possibly something else going on with pcmcia card controllers or other toshiba related issues? The bios is really limiting I can't disable to much (like ide ports...) I'm not sure how to (assuming I can) disable things at boot as kernel params, or even which ones to try.
5) I looked through dmesg - no errors listed in it.
Again system worked great under 704, I just can't find if there was a particular change to 710b3 that did it.