Ok so an update for any future Comcast users: Apparently their 25/2 plan is not good enough to stream out a UI3 window, at least in my case. You may want to check your particular upload speeds, as mine was just not good enough. I was dropping and losing connection constantly. Not only orange clocks, but red critical network error windows in UI3. It seems that Comcast's cheapest plan upload is very bad. I was barely hanging on to 1Mbps with constant drop outs to 200kps and lower. Entirely useless. YMMV.
I'm still within the 30-day period to cancel so I upgraded to the 60/5 plan and instantly the problem was fixed (for the hour or so before reporting this). Steady 5Mbps no problem and sometimes more. I'm still locking it down to 950kbps as the difference between that and full bore 2-5Mbps is negligible for live views. No sense in wasting bandwidth when you're capped at 1TB/mo.
If this stays reliable for the next couple of weeks, I may just keep it. If not, I'll dump Comcast and go back to AT&T (no data caps with U-Verse TV).
Thanks everyone for the help!