I just set a system up for a client and the range is only about 20ft.

Now I had the mrf300 in my house and could be about 100 ft away with perfect commands. I do have all the ir turned off on the remote. The ir levels for the components are set to high. ( I probably should turn down the cable level ). And I tried the extender by the tv and in the equipment rack, and also behind a speaker with little success and a decent amount of interference. The tv is a 52 lcd if that matters.

I am going to change it out with a mrf 350..............i am hoping this will solve the problem..........................Any thoughts on this?

It might help if you mentioned what equipment is giving you trouble. . .

The "GAIN" adjustments on the 300 and 350 are different.
On the 300 the base setting (as low as it will go) is still very powerful, it's about like a standard Xantech unit. Turning it up really overpowers most equipment, especially cable boxes.
The 350 has true attenuation on the dial, the middle setting is equal to the lowest setting on a 300.

well for one the cable box is not responding to numbers (most likely not associated), the tv responds to the power command most of the time. The tuner on zone 2 for the denon 2307 is also not responding 95 percent of the time.

Equipment
Sharp lc 52d62u
Denon 2307 CI
Comcast Motorola (model unknown) non-dvr w/ dvi out

Everything else works very well, just not the range I'm used to on this setup, only about 20 feet on a good day.

Right now the ir levels are all maxed (could be a problem), ir from remote is disabled, and ir commands are sent to all components. Rf sens if set just below where the light will come on.

Hopefully this clears it up for anyone with suggestions.