Q: Has API any settings that may influence the Dirty flag of the Inventor documents?
A: Since Inventor 11 there is a setting that is affecting the true/false behavior of the dirty property. In UI this setting is on the Save tab of the Application Options: "Prompt to save for re-computable updates". This flag is unchecked by default. It specifies whether a prompt to save the document should be displayed when the document is closed without being explicitly saved after any recomputable changes. The API exposes this option as SaveOptions.PromptSaveForRecomputableChanges.