It's kind of funny alias created OBJ and Maya and yet it seems maya has the hardest time dealing with obj files even ones created within maya.
Have you looked in the script editor for any error messages when importing the obj.
I am guessing that you did load the obj plugin.
Did you check the outliner? I have on many occasions had a model load but just not be in frame. If you see an odject was loaded but is not visible simply select the object n the outliner and then press the f-key to frame all and see if that works.
-ram
"If I have seen further it is by standing on the shoulders of giants." Sir Isaac Newton, 1675