It's difficult to say from just your description, but it's worth checking that the option for hardware fill isn't checked in the setup. If you use hardware fill you may not see it if the viewer you're using doesn't support it.
When I created a copper pour area I just clicked on the properties and clicked on the "filled" option. (we could probably say that this should have worked as well)
After reading the help files it appears that the proper way to do it is to right click on the area and select "pour coper"
By the way I found the option to create a hatched coper pour. Anyone knows the benefits from it (if there are any)?
I'll leave the question about the benefits or otherwise of hatched copper to someone else, but in response to the point about setting the copper pour area to filled, I can say that this is a mistake in our Properties dialog. Until you mentioned it, I didn't even realise you could set an area as filled, so I can understand why you thought this would actually produce some copper in the Gerber file. I have logged this for the dev guys to sort out.