Totally new to Arma scripting, but I'm a full stack developer picking this up as a hobby.
I'm curious to see what this really turns out to be, but I'll suspect it has to do with one or both of these two things:
1. without looking at source, does the math that calculates the slew account for rounding errors the engine may be having?
2. It's related to this quirk of the arma 3 engine: http://killzonekid.com/arma-scripting-tutorials-scheduler-and-namespace-switching/
If someone can clearly identify why either of these can't be a cause, I'd be curious to know how far off I was.