I've tested this on Carrara 5.1, no problem loading it as a single primitive vertex object. Looks good even without further messing with crease angles.

I've also used Amapi 6.1 and it loads as expected as multiple objects, but the Weld tool easily brings it all together into a single object.

If you dont have Amapi 6.1 I highly recommend you get it, it's free and still works like a charm on Windows XP. You can find it a polyloop.com (formerly eovia3d.net). I also have details and tutorials at http://www.thebest3d.com/amapi - as a Bryce user you probably should know that Amapi has long been a favorite modeler for none less than Brycetech. He also made and sells Amapi tutorial CDs.