Well I'm glad I'm not the only with these problem's. I have an MX-3000, I started with the MRF-250 and then moved to the MRF-300. The 300 seems a little better but I have the exact same problems as described above. It seems to me that the dimmer light on the RFX is an interference problem, in my room there seems to be very small area's that are troublesome, if I move the remote 2" it will then start to work correctly. I have the RFX set to the lowest setting and in testing antenna showed no interference.

I also get the few second freeze, I am uncertain if the 2 problems are related or not. One thing I did notice is that battery voltage may play some role as when I first take it off the charger it seems to work well and as time goes on it gets worse, at this time the battery meter is usually down to 80%.