If you don't mind the upfront cost, ditching the leased box altogether and going with a TiVo is an option. The UI and overall experience is infinitely better, although you won't have access to PPV and some on demand if that's a factor.
I'm located in Beaumont Texas. The model I have is a Motorola.
I responded to your PM. The other thing that I forgot to mention in my PM would be to consider getting a tech out to check signal strength and that removing the splitter may help with this. A new box will not solve bad signals.
I'm sorry my previous box was a motorola, this one is a Cisco 8640HDC. About a year ago a TWC tech came out and ran a new coax from the pole to my house and a couple months ago I had a tech out and he tested the outlet that feeds the box and modem and was getting a good signal.