Since it's DD-WRT and that's all over the map without a manual for your product I have to share the usual.

Client Isolation, Firewalls and that question that Windows asks when you connect to the hot spot. Here's a link about that last item.
Read around the "Turn on Network Discovery and File Sharing." at http://www.groovypost.com/howto/windows-8-file-history-network-location/

If you raised any firewall or block this, all the above can happen.
Bob