I have actually been considering switching TO FIOS because the FIOS rep told me they now had an additional tuner unit (like a very small set top box) that decrypted the signal and allowed the RTV or TV to tune the channels directly. These are also cheaper that the regular stb @ $3 or $4 each/month. This, he claimed, would allow me to receive all regular (non-digital/HD and non-OD) channels including all extended channels, such as FSC and BBC America, and premium channels, such as HBO/Starz/etc. If it works as claimed this might solve your problem.
3RTV over ethernet + DVA show server over buffalo wireless