I'm running Debian/Etch on an AMD64 system. I have set up an NFS share
on another Debian system. I can mount the share OK but when I try to
copy files from it to my AMD64 system, the process stalls after a few
hundred K. I can click the cancel button on the Konqueror copy dialogue
and the dialogue closes. However, at this point I can't even look at the
directory containing the mount point.

If I try to umount it, I get a "device busy" message. fuser -m
/mnt/point never returns and neither does lsof. ksysguard also hangs
when I start it up (but top doesn't).

I'm looking for two things:
any ideas on why the copy stall is happening, and
any ideas on fixing/killing whatever is causing umount from failing.