I tried this and it worked better (ping from a pc yields now <10ms was previously >100ms) but after a few minutes inactivity I have to 'activate' the connection, see the log below.
With putty, the first time I have to reset the terminal and then it connects.
It seems that after a certain period of time the SSH connection 'falls asleep' and has to be woken up.

It is on a Sitecom WL-114.
On the Linksys WRT160N the problem does not occur so I left the setting to power saving on (is configurable per connection).


Pinging 192.168.1.171 with 32 bytes of data:

Request timed out.
Reply from 192.168.1.171: bytes=32 time=18ms TTL=64
Reply from 192.168.1.171: bytes=32 time=5ms TTL=64
Reply from 192.168.1.171: bytes=32 time=4ms TTL=64

Ping statistics for 192.168.1.171:
Packets: Sent = 4, Received = 3, Lost = 1 (25% loss),
Approximate round trip times in milli-seconds:
Minimum = 4ms, Maximum = 18ms, Average = 9ms

C:\Documents and Settings\klaas>ping 192.168.1.171

Pinging 192.168.1.171 with 32 bytes of data:

Reply from 192.168.1.171: bytes=32 time=4ms TTL=64
Reply from 192.168.1.171: bytes=32 time=4ms TTL=64
Reply from 192.168.1.171: bytes=32 time=5ms TTL=64
Reply from 192.168.1.171: bytes=32 time=4ms TTL=64

Ping statistics for 192.168.1.171:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds: