Can't nfs mount Debian box

[fh@crosslink.net ()]

Hi...
   
I'm having trouble nfs mounting a Debian box from other machines... 'ps
-aux' indicates rpc.portmap, update, nfsiod (4 instances), kerneld,
inetd, bootpd, rpc.nfsd, rpc.mount, rpc.ugidd.  Other processes seem to   
be working well (apache, netscape, in.telnetd, bash, emacs)...  Still a
variety of machines (linux, NeXT, Sparc) can't mount correctly configured    
/etc/exports (i.e. '/   trusty(rw,no_root_squash)...  

What can I do to ferret out this problem?  Any immediate clues as to
what's going on?

TIA