AT, send me a few of your models in DOGA format, and say what Version you used to make them. I KNOW I got a DOGA model into Bryce once and if I can get it into Bryce I can get it into almost anything.
AT, I suggest you to make better - put several of your obsolete models availiable for public (in all formats you can do). We can arrange some kind of brainstorming against this problem, trying to open it in different modellers, using some tricks to lower poly count, etc.