Definitely this is Samba issue with speed... sounds weird, but it is...

Continues the story of GuruPlug strange behavior.
eth0 config:
sheevaplug-debian:~# ifconfig
eth0 Link encap:Ethernet HWaddr f0:ad:4e:00:28:47
inet addr:10.10.10.135 Bcast:10.10.10.255 Mask:255.255.255.0
inet6 addr: fe80::f2ad:4eff:fe00:2847/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:4437530 errors:0 dropped:0 overruns:0 frame:0
TX packets:3960071 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:513740696 (489.9 MiB) TX bytes:3861738168 (3.5 GiB)
Interrupt:11
sheevaplug-debian:~# ethtool eth0
Settings for eth0:
Supported ports: [ TP MII ]
Supported link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Full
Supports auto-negotiation: Yes
Advertised link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Full
Advertised auto-negotiation: Yes
Speed: 1000Mb/s
Duplex: Full
Port: MII
PHYAD: 0
Transceiver: external
Auto-negotiation: on
Link detected: yes
sheevaplug-debian:~#
Network speed test via netcat:
sheevaplug-debian:~# netcat 10.10.10.117 12345 -c "dd if=/dev/zero count=2000000"
2000000+0 records in
2000000+0 records out
1024000000 bytes (1.0 GB) copied, 87.4634 s, 11.7 MB/s
sheevaplug-debian:~# netcat 10.10.10.117 12345 -c "dd if=/dev/zero count=2000000"
2000000+0 records in
2000000+0 records out
1024000000 bytes (1.0 GB) copied, 88.6938 s, 11.5 MB/s
sheevaplug-debian:~#
100Mbit speed over the Gigabit interface?
Neighbor PC to Laptop within the same switch are doing 40+MB/s transfer...
Any ideas?