My D-link PCMCIA card (ne) seems to suffer from buffer overruns when
there is a lot of network activity.

I've tried exchanging the card with another and the same thing happens.

A tcpdump is sufficient to get

/netbsd: ne0: warning - receiver ring buffer overrun

Moreover, (this is with NetBSD-1.5.1_BETA), using nfs is painful. A
recursive directory copy from an nfs mount to a local directory causes
quite a few buffer overuns. It seems impossible to ^C or ^Z this
process. (I managed to kill it on one occasion and then any access to the
NFS mount hangs.)

A reboot whilst such a copy is going on freezes at the "syncing disks ...done"
stage.

Any suggestions...?  

cheers,
-- 
Chris