Welcome to LQ!
I've had this problem when playing with an embended system with uclinux 2.4.
I had a 3com switch which sometimes stopped working. I did look for the problem, I tried with an other switch (the exact same model, but a different part number, newer) and the problem disappeared. It was the only problematic switch out of 10. Maybe you're PHY is loosing link or a duplex problem?? Electrical problem??? I did not dig into the problem as changing the switch solved it.
Still this problematic switch seemed to work well with PC.
So I can just tell you that it happened to me... maybe borrow someone else's switch or hub.
Last edited by nx5000; 11-10-2005 at 04:39 AM.