Well, we were scheduled for an 04S replacement this week but cancelled it following the issues being raised here about the latest version.
Our third set of 03S bellows leaked and we were put down for the 04S swap. However, after several times used last year the leaks appear to have stopped.
This year we have used the bellows in persistent rain, wind, day after day of rain and they've been 100 percent waterproof.
Seems like it would be wrong to swap for something else now so we've closed the warranty case.
This does suggest it's some kind of manufacturing artifact because I was one of the camp that believed every 03S would leak given the right circumstances. Clearly not.
I've heard wrong needles, wrong thread, hot needles etc.
But my view has changed that this is a manufacturing issue as opposed to a design issue. Although changing the design (like adding seam sealers) may ultimately provide the solution for a manufacturing issue.
For now, it's happy camping come rain or sunshine!!!