Network problems

I have a strange problem with my Dell Inspiron Laptop.  The network card
will stop responding to all network traffic.  This happens very
regulally, though without any obvious pattern.  Sometimes it only
appears as slight packet lose though normally the network connection
goes completly.  But then at other times the connection stays up for a
resonable time.  I have tried different cables, hubs, etc but to no
avail.  

Link status doesn't seem to get dropped, only IP.

When the connection gets dropped doing an ifconfig down/up on the
interface does ?

Unplugging and then inserting the network cable will restore the
connection for at least a few seconds.

I am running a recent current:
FreeBSD opal.macaroon.net 5.1-CURRENT FreeBSD 5.1-CURRENT #0: Fri Sep 19
21:59: 12 BST 2003 root_at_aalto.macaroon.net:/usr/obj/usr/src/sys/OPAL
i386

The network card is an integrated intel card, (fxp0):

fxp0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
        options=3<RXCSUM,TXCSUM>
        inet 10.1.10.200 netmask 0xffffff00 broadcast 10.1.10.255
        ether 00:20:e0:69:50:3c
        media: Ethernet autoselect (100baseTX <half-duplex>)
        status: active

Unfortunatly I can't remember when it started happening.  I have been
tracking current weekly for the past few months.  It certainly seems to
be getting worse though.

Any help would be much appriciated.

Cameron