Response from Humax
Thank you for contacting Humax.I'm sorry that you are having this issue with your Humax Box. I can see in that thread you have already confirmed it is possible to connect with a shorter password, and you also have a guest network setup. If you are security conscious you could consider also adding the FVP's mac address as a security check for the guest network. I will pass on the concerns regarding maximum password length to our development team.
Best Regards,
Stephen
Humax Customer Support
I use MAC addresses as well but disable them if I'm adding a new device to the network. 
