(For what it worth… V4 and probably V3 as well) I have noticed that after modifying a master page and updating ALL related project files, changes don’t take effect - I have to explicitly SAVE ALL FILES (even if they are not loaded into the editor) - notifications to that effect then show up on screen.
Caveats: an error message appears during the aforementioned update advising about update error in modifying 3 files - perhaps files’ save is only made if the operation as a whole is completed successfully (IMHO, each successfully updated file should be saved immediately, not as a batch)
Please advise if you fared better or have a workaround…