Well, we finally tracked down the issue. Many thanks to Arsla, the PixelEx developer, Gustavo Lanzas, P1xels’ developer, and the folks at Zippykid, our ISP. It turned out to be a very minor thing in the “a records.” But we couldn’t have gotten to that with a bunch of detective work on the part of all of them, eliminating things, testing, etc.
What a relief.
So … please start using PixelEx again. I apologize for any inconvenience.