port not reading macports.conf?

[M A]

I seem to be having a problem with port not reading my
~/.macports/macports.conf. Specifically, this macports.conf
file is identical to the one in /opt/local/etc/macports except with
the line "binpath
/usr/texbin:/opt/local/bin:/opt/local/sbin:/bin:/sbin:/usr/bin:/usr/sbin:/usr/X11R6/bin"
appended at the end. Yet, when I try to install a port with a
dependency like "bin:tex:teTeX" (eg latex2rtf) it tries to install
teTeX.
Yes, the tex binary is in /usr/texbin and I selfupdated this morning.
If I put that line in /opt/local/etc/macports/macports.conf
then it works as I expect and installs latex2rtf without trying to
install teTeX. I also know that sometime before the switch to
MacPorts 1.5 it worked to put "binpath..." in my user macports.conf
file, but I'm afraid that I can't be any more specific about
when this stopped working. Is there a reasonably good way to diagnose
whether there is something wrong with my setup,
or is this a bug?

Mark A