Point being, you can see the GAL has been changed, the one with a white sticker on this showing the problem GAL. The one without the sticker, is the one out of my test board. That GAL will run all day and the machine will not crash.. And yet stick some other GAL in, and it barely gets past the Atari logo.
I spent two weeks on this last year to trying figure out the reason why. It has nothing to do with the speed of the GAL, all the rise and fall times look exactly the same between a working and nonworking GAL. I pretty much cannot find any noticeable difference between the two.
While I have been using dubious sources of the GAL22V10... I also tried the ATF22V10 As they are still in production, but if I remember rightly I had even more trouble with those. The original batch of GAL's in the original V1's sold a few years back, all works perfectly fine. I really don't know why. But batches of GAL's I bought last year, basically saw something like 1 in 20 working. With them costing a minimum of £2 each.. thats £40 worth of chips and £40 ontop of the booster price.
So while I have 50 of these boosters built, and I regularly get people asking me "when will it be available".. They will be available when I find some GAL's which work.. which in about two years so far I have been unsuccessful in doing.
I will however spend the next couple of days investigating this issue again...But I am really not sure what else I can do which I have not already tried..
maybe next year I may ask 
because this is basically very specific scenario which again generally only happens with 3D games like frontier which use a lot of integer divisions. A similar thing can also happen with ROM access no doubt.