[BUG] Something going wrong when rewinding

[namida]

Was making a solution replay for Mayhem 20 of LP3D, encountered some cases where the alive lemming count went down after backwards framestepping (then come right after further steps). I suspect some of the "checkpoint" save states aren't being erased correctly but haven't looked into it yet.

Using the latest source at the time, which has a few changes from 0.0.25.0.

[namida]

Have encountered this again. Haven't shed any light on the cause, but I did confirm that an extra lemming was actually missing (as opposed to merely an incorrect count being displayed).

[namida]

I did identify one plausible cause of this and fixed it, but it's not definite. I haven't been able to intentionally trigger this bug by any means, so it's hard to say if it really is fixed or not.