high ping on local AirportExpress network

[Tex-Twil]

Hi,
I realized I have a high ping when on my local wifi network. I have a MBP and my gf has a MB.

When I ping the MB from the MBP:

 ~ $ ping 10.0.1.3
PING 10.0.1.3 (10.0.1.3): 56 data bytes
64 bytes from 10.0.1.3: icmp_seq=0 ttl=64 time=723.946 ms
Request timeout for icmp_seq 1
64 bytes from 10.0.1.3: icmp_seq=1 ttl=64 time=1004.079 ms
64 bytes from 10.0.1.3: icmp_seq=2 ttl=64 time=565.695 ms
64 bytes from 10.0.1.3: icmp_seq=3 ttl=64 time=7.407 ms
64 bytes from 10.0.1.3: icmp_seq=4 ttl=64 time=1004.978 ms
64 bytes from 10.0.1.3: icmp_seq=5 ttl=64 time=634.663 ms
64 bytes from 10.0.1.3: icmp_seq=6 ttl=64 time=556.471 ms
64 bytes from 10.0.1.3: icmp_seq=7 ttl=64 time=170.154 ms
64 bytes from 10.0.1.3: icmp_seq=8 ttl=64 time=399.332 ms
64 bytes from 10.0.1.3: icmp_seq=9 ttl=64 time=320.648 m
Request timeout for icmp_seq 20

But when I ping the AirPort Express directly it is fine:

~ $ ping 10.0.1.1
PING 10.0.1.1 (10.0.1.1): 56 data bytes
64 bytes from 10.0.1.1: icmp_seq=0 ttl=255 time=3.160 ms
64 bytes from 10.0.1.1: icmp_seq=1 ttl=255 time=4.588 ms
64 bytes from 10.0.1.1: icmp_seq=2 ttl=255 time=3.227 ms
64 bytes from 10.0.1.1: icmp_seq=3 ttl=255 time=0.959 ms
64 bytes from 10.0.1.1: icmp_seq=4 ttl=255 time=3.197 ms
64 bytes from 10.0.1.1: icmp_seq=5 ttl=255 time=4.079 ms
64 bytes from 10.0.1.1: icmp_seq=6 ttl=255 time=1.139 ms
64 bytes from 10.0.1.1: icmp_seq=7 ttl=255 time=3.220 ms

Any idea where this could come from ?

btw:
UMB: Leopard
UMBP: Snow Leopard

Both are like 3m from the AirportExpress, no walls in between.
Tex

 

[Tex-Twil]

I also tried to ping from the other direction (ie from the MacBook) and the problem is the same. So sum up:

MB ping MBP SLOW
MB ping AirPort OK

MBP ping MB SLOW
MBP ping Airport OK

 

[Tex-Twil]

Hello,
I reopen this topic. I've got a new MBP meanwhile but the problem is the same. It's very annoying when I SSH to a local server, The connection is then laggy.

Tex