[Twan]

I've asked the same question sometimes ago. Like said disease immune creatures can have the disease afflication but without effect (except allowing them to have benefit from a fever fetish).

In addition to cold blooded ones, it appears that creatures with swamp survival at least are immune to miasma diseases. I've also tested a master druid, who has not swamp survival but a PR of 100 and he didn't get diseased in 50 turns, but I can't say if PR has anything to do with it (according to some old d2 threads PR worked against the miasma effect, so perhaps a PR ring is sufficient to make any pretender immune ?).