First of all, let me just say this is an awesome plugin! I'm going to switch from WooCommerce because of how incredibly easy it is to add variations. I love it!
I am having one minor problem. I'm using WP 3.9.1 fresh install with the latest FoxyCart downloaded using the automatic installer.
There is no option to enable comments on product pages on my product editing pages. The option is there when I go to add a post or page, but not when I go to add a product. I did check the Screen Options at the top of the page and there is no Discussions check box like there is under posts and pages. Likewise, there are no comment fields on my product pages. I tried switching among the themes Twenty Twelve, Twenty Thirteen, and Twenty Fourteen but didn't have any luck. I also tried to create a fresh product rather than editing existing ones and that didn't help either. Finally, I made sure commenting was enabled in the settings and it was.
I am wondering if maybe this has something to do with a recent change in WordPress core.
Thanks for looking into it and for the awesome plugin!