I'll look into it soon, and I have an old save perfect to investigate with.
Attached is a screenshot that have these numbers:
Total culture:
100 185 440
Next level at:
40 000 000
Difference:
-60 185 440
Greater culture + normal culture from the old save is correctly translated to the new single long long culture variable.
100 greater culture + 185 440 culture
This is what the save had before the culture storage change.
None of these values would overflow a regular 32 bit integer, but irishhombres screenshot may have had just that for the next level threshold value.
Irishhombre's values:
Total culture:
525 969 287 (probably a correct value)
Threshold:
-416 677 888 (A bug. Negative!! May be an int 32 overflow at work here or a math/logic error in the calculation code)
Difference:
-942 647 175 (This value is correct! -416 677 888 - 525 969 287 = -942 647 175)
It seems the thresholds for when you are supposed to get a new trait is somehow different now, that the old code had faulty logic in how it dealt with greater culture, or perhaps the new code was badly converted to not deal with greater culture.
Anyhow, I'll look into the matter tomorrow I think. My gut tells me it should be easy enough to fix.