bison and bison2 conflict

[Anthony M. Agelastos]

Hello,

Basically, I want to have bison and bison2 coexist peacefully on the  
same machine. I installed math/opendx and it requires bison. Then, I  
try to install editors/openoffice.org-2.0 and it requires bison2. I  
get the message:

===> bison-2.1_1 conflicts with installed package(s):
           bison-1.75_2,1

           They install files into the same place.
           Please remove them first with pkg_delete(1).
*** Error code 1

Ideas? Workarounds? Would something like

make install PREFIX=/usr/local/bison2 work?

If so, how do I ensure in pkgtools.conf that upgrades to bison2 will  
always do that? Thank you all for your assistance.

-Anthony