OK, well, it looks like I already figured out a work around for you that WILL work and it seems so far to work quite nicely to boot! :)

What I did was, i loaded in the Greek Ruins.
I made sure that it had most if not all, Quads for polygons, which it did.
So, I exported that out in the OBJ format, and sure enoughm, you're right, it exports it out the same way it shows up in Poser (I'm using Poser 6 until I can afford 7).

Sooo, the trick is to do this:
Export you object as a 3DS format.
This will guarenty that you WHOLE object comes out with trippled polygons.
Clear that Poser object out (new scene).
Import that 3DS object you just exported out and guess what, ALL the trippled polies will still stay intact.
Sooo, NOW you can export that again in the OBJ format this time and this time it will 
save with ALL of the trippled polies intact with the OBJ formatted object and there ya go!
All nice and ready for using in Ivy Gen for you :)
Don't worry about things like whether or not textures/materials and all that 
show up on your objects, as they aren't needed in Ivy Gen anyway, you're 
only using the program to mgenerate your Ivy with anyway.
Once you make the Ivy and export that out (also as an OBJ formated object, 
it's only format it can save to) then, simply load in your Ivy into Poser and enjoy!

Hope this helps? :)

...................md :)