Any of those environment factors being the cause of the all 1s bug doesn't make much sense, unless there is a bug somewhere violating code encapsulation.
The one factor I've noted in common for the boards suffering this bug is php5.4. Bug that kind of bug from php5.4 when php 5.3 and php5.5 both run the dice code correctly also doesn't make much sense.
I'm using mysql on the back end. What databases for your boards?
Just went though a few rounds of debugging on the install. I have no idea all of what was different between the install and fix bbcode records, but what I just committed to github appears to work for install.
Pasting that first seed into my copy of the board I get 4,6,5 => 15. In any case that's one more suspect eliminated.
I was about to ask if your servers were 16 or 32 bit, but I have properly working copies of this extension on one of each. Running some flavor of linux on both. What operating system there? Shouldn't make a difference but I'm out of rational explanations.
Well, as I have said earlier the code broke for me when updated to 0.8 - and if I revert to 0.7 all is working again.
The cause is in that code change.
Can shepski run 0.7 and see if the works for him?