No Altoona triangle is involved. This issue is commonplace, though more so with some brands of tubes than others, but it's happening all over. Almost every dealer has run into it, and it's commonly discussed on various forums.

I visit lots of shops in the course of my business, and am finding it harder and harder to find tubes that aren't prone to the problem.

Does it happen to everyone all the time, of course not, but is isn't rare either. Different rims, and different rim/tire combinations worsen the problem, but it's something that didn't happen at all 5 years ago, and is now commonplace.