So I've been playing the powerslave mission from the kingdom of the sands level on madness difficulty, trying to achieve the "win in 300 seconds" objective. I'm pretty sure I've beaten this mission in less time on several ocations but the game still didn't clear the objective. So my question is this: there's an option to accelerate time during battle (top right button), does this button, if used, affects this kind of objectives? Does this happened to anybody else? How does the game computes time?

(sorry for the bad english)