My instant reaction would have been that it has something to do with the temps and humidity that people are keeping them at but in retrospect I'm not so sure about that anymore..... what are the chances that people from different provinces and therefore different atmospheric conditions would all be having the same issue.
That said, it would possibly be useful if everyone posted the keeping conditions of all the ones that died to see if we can pick up any sort of pattern.......

Mine apparently grew up as a burrower (Farking weird as hell) as when I bought it, it had a big burrow at the bottom of the cage. Thus I kept it as a terrestrial burrower, but still had a big ol chunk o wood for it to climb on, yet never did. Kept moderately dry with a big water bowl, with the occasional spray of water thrice a week.

Just a thought, and Im a noob so its probably a dumb one but what about ventilation?

The internet references to this species seem to agree that the species is a close-to-tree-tops arboreal so wouldnt it prefer seriously good air? Slings would be more tolerant of less but as they get bigger and need more oxy?

Our big female is still perfectly healthy.. (touch wood).. She came from Durban about a year ago..just a thought to maybe help out with the search.
This sucks!!! But our male did die for no reason by someone else. Dunno whats going on!!

Yeah, four separate egg sacks but it has been years since these were imported, so the chances of the same breeding stock being used over and over again is incredibly high, same with all the other mutants and stuff around these days

F1refly what do you understand when using the word inbreeding?