i currently use the universal automator and mrf-100a expander
urc-automator http://www.universalremote.com/product_detail.php?model=52
and the mrf-100a expander http://www.universalremote.com/product_detail.php?model=49

i just got the mx-600 new in the box on craig's list for $85
mx-600 http://www.universalremote.com/product_detail.php?model=53

the problem is that i have comcast hd boxes in two separate rooms... so when i use the mx-600 in the basement, the rf signal is received by both the rf blaster in the basement and the rf blaster of the mrf-100a expander up stairs. so the short version of the problem is that is i change the channel in the basement, it changes the channel up stairs.

with these remotes, i can not change the rf frequency. does anyone have any advice on how to use both remotes without turning the blasters off at times? if not, it looks like i will be going back to craig's list to get back what i paid for it

thanks