Overriding TMPDIR with -T not working

[Ed]

My cvs commands are failing due to lack of temp space.  I'm trying to 
override the TMPDIR setting (default /tmp), but not having any success.  My 
cvs root is on host 'cvs1', and on a remote machine, 'dev1', I'm running 
the following command:

        cvs -T /users/tmp diff

My env on dev1 contains the following:

        CVS_RSH=remsh
        CVS_SERVER=/usr/bin/cvs
        CVSROOT=:ext:address@hidden:/cvsroot

I'm using cvs 1.11 on both client and server.

Any clues?