If this is driving any other beginners nuts, here's another post in the hope that it might just increase the chances of someone finding it:
I couldn't for the life of me figure out what was going wrong when trying to import OBJ files; I'm on a Mac, but even so, I heeded the advice to remove all spaces from the file path, to no avail.
I found the answer here:
http://www.sidefx.com/index.php?option=com_forum&Itemid=172&page=viewtopic&p=54237&sid=a2a64038c63a4de42a7916a68b792de6
here's what it looks like in the import dialogue box:
Hope this helps someones