Orbit(Periapsis) < 100000 returns false on the launch pad, for example, yet it's certainly not true that the Pe is greater than 100000.
Orbit(Periapsis) returns NaN when the periapsis is negative, but this cannot be detected in Vizzy.
Most programming languages do not allow testing against NaN (x==NaN will always return false), rather you need to use a special function.
So this is really too bugs, that Pe is not negative on the launch pad, and that NaN cannot be detected.