Periodic delays in ping time

I've been noticing occasional lack of responsiveness with a linux
machine and just noticed a strange ping delay to and from it (see
attachment). The ping time will be below 1ms for a while, and then
suddenly it will go over 1000 for a few consecutive pings. This
behavior repeats every half minute or less.

I am also getting many "NETDEV WATCHDOG: eth0: transmit timed out"
errors in my logs.

Rebooting the machine helps the problem for a few days, but the
problem returns after a while again.

Does anybody recognize this as a symptom for a problem. My first guess
is a faulty network card or driver, but what do I know...

Thanks,

Nathan


System info:
Fedora Core 5
Kernel 2.6.19-1.2288
Ethernet Controller: Linksys NC100 Network Everywhere Fast Ethernet
10/100 (rev 11)
Drivers: tulip (...I think)

64 bytes from 10.0.0.10: icmp_seq=718 ttl=64 time=0.784 ms
64 bytes from 10.0.0.10: icmp_seq=719 ttl=64 time=0.373 ms
64 bytes from 10.0.0.10: icmp_seq=720 ttl=64 time=0.769 ms
64 bytes from 10.0.0.10: icmp_seq=721 ttl=64 time=0.758 ms
64 bytes from 10.0.0.10: icmp_seq=722 ttl=64 time=6170.335 ms
64 bytes from 10.0.0.10: icmp_seq=694 ttl=64 time=34181.533 ms
64 bytes from 10.0.0.10: icmp_seq=724 ttl=64 time=4170.576 ms
64 bytes from 10.0.0.10: icmp_seq=725 ttl=64 time=3170.454 ms
64 bytes from 10.0.0.10: icmp_seq=726 ttl=64 time=2170.381 ms
64 bytes from 10.0.0.10: icmp_seq=727 ttl=64 time=1170.362 ms
64 bytes from 10.0.0.10: icmp_seq=728 ttl=64 time=170.204 ms
64 bytes from 10.0.0.10: icmp_seq=729 ttl=64 time=0.731 ms
64 bytes from 10.0.0.10: icmp_seq=730 ttl=64 time=0.725 ms
64 bytes from 10.0.0.10: icmp_seq=731 ttl=64 time=0.812 ms
64 bytes from 10.0.0.10: icmp_seq=732 ttl=64 time=0.688 ms
64 bytes from 10.0.0.10: icmp_seq=733 ttl=64 time=0.669 ms
64 bytes from 10.0.0.10: icmp_seq=734 ttl=64 time=0.519 ms
64 bytes from 10.0.0.10: icmp_seq=735 ttl=64 time=0.655 ms
64 bytes from 10.0.0.10: icmp_seq=736 ttl=64 time=0.813 ms
64 bytes from 10.0.0.10: icmp_seq=737 ttl=64 time=0.729 ms
64 bytes from 10.0.0.10: icmp_seq=738 ttl=64 time=0.676 ms
64 bytes from 10.0.0.10: icmp_seq=739 ttl=64 time=0.505 ms
64 bytes from 10.0.0.10: icmp_seq=740 ttl=64 time=0.802 ms
64 bytes from 10.0.0.10: icmp_seq=741 ttl=64 time=0.329 ms
64 bytes from 10.0.0.10: icmp_seq=742 ttl=64 time=0.828 ms
64 bytes from 10.0.0.10: icmp_seq=743 ttl=64 time=0.822 ms
64 bytes from 10.0.0.10: icmp_seq=744 ttl=64 time=0.735 ms
64 bytes from 10.0.0.10: icmp_seq=745 ttl=64 time=0.814 ms
64 bytes from 10.0.0.10: icmp_seq=746 ttl=64 time=6165.370 ms
64 bytes from 10.0.0.10: icmp_seq=723 ttl=64 time=29168.447 ms
64 bytes from 10.0.0.10: icmp_seq=748 ttl=64 time=4165.306 ms
64 bytes from 10.0.0.10: icmp_seq=749 ttl=64 time=3165.204 ms
64 bytes from 10.0.0.10: icmp_seq=750 ttl=64 time=2165.048 ms
64 bytes from 10.0.0.10: icmp_seq=751 ttl=64 time=1164.650 ms
64 bytes from 10.0.0.10: icmp_seq=752 ttl=64 time=164.496 ms
64 bytes from 10.0.0.10: icmp_seq=753 ttl=64 time=0.527 ms
64 bytes from 10.0.0.10: icmp_seq=754 ttl=64 time=0.731 ms
64 bytes from 10.0.0.10: icmp_seq=755 ttl=64 time=0.656 ms