In summary...if anyone in the future is searching through these forums because they are having trouble with their UPB switches intermittently working. This is what I learned and would share...
Assumption is that you have your switches all programmed correctly.
1. Have regular old incandescent bulbs available. Start swapping your LED/CFL bulbs with the incandescents to see if everything starts working. Just because the LED/CFL bulb turns on, that doesn't mean it is compatible with your switch. I learned this the hard way after spending a day or so troubleshooting. Even more confusing...an incompatible bulb may cause your system to 'sometimes' work. This masks the issue as it is not clearly the problem.
2. Get Upstart. Just do it. Its free. I did what many others did and started with the thought that I would just do everything through the Omni iie and pcaccess. That will get you there, but Upstart will give you a whole lot more troubleshooting ability and will let you monitor and look at your signal levels throughout your house. The only real cost is a serial convertor and cable to your PIM. I got this for $2 on amazon with $5 shipping.
3. If you have any issues with signal levels...and you are thinking of getting the Phase Coupler....I would say just go for the Repeater. They are now within $50-$60 in price and well worth the extra money. My phase coupler made no difference at all to my levels (you may have different results), but the repeater had a dramatic impact to improving my signal levels. (again...you may have different results.)
4. Last point...I concur with both Pete and Neil. Home Controls was awesome. Great service and awesome tech support department. I highly recommend.
Again, thanks to everyone who helped me in this learning experience!
Edited by lvmikel, 03 February 2015 - 04:40 PM.