Ping oddity

[Michael McGoldrick]

Hi,
On a recent -current kernel, when running ping over a ppp link I get lots of
messages like this:
wrong data byte #0 should be 0x3f but was 0x3e
cp:3e 5e 99 3e ed c3 5 0 
        8 9 a b c d e f 10 11 12 13 14 15 16 17 18 19 1a 1b 1c 1d 1e 1f 20 21
22 23 24 25 26 27 
        28 29 2a 2b 2c 2d 2e 2f 30 31 32 33 34 35 36 37 
dp:3f 5e 99 3e f2 eb 5 0 
        8 9 a b c d e f 10 11 12 13 14 15 16 17 18 19 1a 1b 1c 1d 1e 1f 20 21
22 23 24 25 26 27 
        28 29 2a 2b 2c 2d 2e 2f 30 31 32 33 34 35 36 37 
Whenever something else is using the link (fetch, Mozilla etc.) 
When nothing else is touching the network, ping is fine:
64 bytes from 216.239.51.99: icmp_seq=120 ttl=51 time=650.374 ms

Any idea what could be causing this?
FreeBSD uriel.fakedomain.net 5.0-CURRENT FreeBSD 5.0-CURRENT #29: Fri Apr 11
21:03:55 BST 2003     root at uriel.fakedomain.net:/usr/obj/usr/src/sys/URIEL
i386

Using ipfw.

-- 
Michael McGoldrick: mmcgoldrick at linuxdriven.net