i just recently setup a msc400 controller with an mx980 and so far everything works pretty good but i've noticed that when you send a command to the msc, its blue light blinks about 1 second after the button is pushed on the remote. so lets say that i want to scroll through a menu, it takes about 1 second intervals to scroll. pushing the button multiple times doesn't cure this as the msc will just wait for the command to go through and then issue the next command. now in my other system that uses an mrf260 and mx450 remote, the codes are learned through the remote but the response is instant. are there any workarounds? would loading the commands into the remote itself (as opposed to into the msc400) result in quicker button response?

No delay on my msc-400.

Sounds like RF issues to me?

Reposition RFX-250 if RF LED is flickering or illuminated to improve
reception.

i dont think its an rf issue. if you notice when you send a command, the blue led on the front of the msc will blink and you must wait for that light to go out before it can issue another command. in my case, my cable box has a guide menu that when using my mx450 and mrf260 is instant response when scrolling. with the msc, i noticed that if you click the scroll down or up button twice or three times very quickly, you will only get one command sent. this i confirmed by actually looking at the blue led and seeing that unless the light goes out, it won't send a command that you pushed during the period. im wondering if this is a limitation of the msc or if there are any workarounds for this. i vaguely remeber seeing this issue reported somewhere a while ago but at a loss as to where i read it.

Again, my msc-400 will scroll just fine with no delay and responds to multiply button presses.
If you have no RF-issues and no red light on your RFX-250.

Maybe this may be the problem........
I assume you're sending the codes to your cable box with an IR emitter.
What is your "repeat when pressed" set at; for the buttons you're having problems with?
If the blue button keeps flashing on the msc-400; you may have this set to high? 3 repeats is enough.

It would also help to include more about your set-up.
What cable box are you using and how is it controlled.
Is this the only thing that is causing a problem with delay?

Good Luck!