First, although the 28BYJ-48 motors is supported in SImVim, but I still need to refine algorithm (mostly speed related issues as it is completely different to X27 motors). Additional information about 28BYJ will be placed on the website soon.
As for the problem you have described, it turned out that current version has an issue with full-circle gauges. It happens when stepper jumps through zero-position.
So we need to return to the stepper program again to solve this. As we it will be done we will inform community here.