Ok, I finally solved the problem.
On mechanics, everything was tight except the central tripod shaft ad the azimuth adjustment bolts. Thanks Andrea for that tip. That improved things a bit but I would still loose lock during guiding. Doing John's rap test, the system stopped oscillating after about a sec.
Last night I installed the latest dev. release of PHD2, ran a new calibration and guiding assistant. The wind was about that same as it had been through this entire ordeal so I started watching the behavior of PHD2 very carefully. It was loosing lock whenever the HFD of the guide star dropped so I decreased the min. HFD value to 3.5. That improved things but lost lock would still happen with a good gust. I then opened up the search box to 25 pixels and increased the camera gain to 95, again a bit better. The last move was to remove the uv/ir filter from the guide scope. The filter was giving tight stars but was reducing the SNR. PHD2 seemed to be happier with bloated but bright stars. Now I was no longer loosing lock but the guiding was all over the place. I had taken the suggested MinMo numbers from the guiding assistant and they were pretty large, up around 65 for RA and DEC. Once I dropped those values to about half of suggested, guiding clamed down and was rock solid for the rest of the night.
Thanks to everyone who helped out on this. Hopefully my experience can help others who run into the same issue. PHD2 is simple but not always right. It's worthwhile to get in there and carefully tweak settings if needed for you conditions and system.