I installed firmware version 188.8.131.52 a couple weeks ago after seeing in the release notes that the port forwarding bug where clients would get 'no route to host' was resolved (one of the original posts found here: https://supportforums.cisco.com/message/3512354).
After installing the firmware and confirming it's running I've seen no improvement. I still must reboot my router 2-3 times daily so clients can access the ports that are defined in the port forwarding module.
Please take another look at this - the issue is not resolved and as far as I can tell it hasn't even been improved. Please also let me know of any beta firmwares - anything to put this issue to bed. It's been going on far too long.