I'm happy to report that the sealing and tape provided by Ron has been a succes thus far. However since this trail test at home it's only showered a couple of times while out hiking. So further tests are warranted.
Ron, it did not rain constantly for the couple days I had the shelter up, You misunderstood me, it rained constantly for a few days prior to pitching the Duomid in my backyard. While the shelter was up, it was only showers off and on.
The shelter was in no way, under extreme testing during those two days. It was only very light of and on shower, with one heavy downpour on the 2nd night for half hour.
I always subject all my shelters after purchasing to such tests before a hike, for good reason's. So to get used to pitching the shelter and to check on water proofness.
I suspect the water was coming through those two rows of stitching on the peak, and because the white patches where not sealed to the Cuben correctly this was leaking through on the inside. I feel that if this patch was correctly sealed, this leak would not have eventuated. But this proves one thing, that water does indeed get through the stitching on the peak.