I tried the exporter for 3ds Max 6 in that batch and I couldn't get it to work. I did find this one though:
The direct link for the export plugin is here:
(Download the bin file)
If that doesn't work you can go the long way:
Click on "dotXSI xchange for Max - Export" , then click on "dotXSI4max" (the name seemed a little deceiving to me, more like it was for max 4 and not 6 ). You'll want to download the "bin" file.
I've tried that one out pretty extensively and it's always worked for me.
Also, Softimage has released a free version of XSI for making models for the upcoming Half-Life II. It may also be capable of making models for JO/JA but I'm not very familiar with the program yet, so I'm not sure. It's a fairly large download though.
It can be found on their site here.