@SebastianLarrs thanks for sending the video, which clearly shows a strange delay going on. Unfortunately I’m still unable to reproduce the problem. I tested it on my MacBook Air, on which I can reproduce the laggy scrolling bug reported in another thread, but scriptwriting works fine with no delay. I therefore suspect there is another factor at play.
One thing to try is to turn off spell-checking and spelling corrections via the Edit > Spelling and Grammar menu, and to turn off all auto-correction options in Scrivener’s Settings / Corrections pane. That will just tell us if it’s one of those settings causing the problem - if the problem persists, then it rules that out.
After, that, another thing to try is to go to the Settings panel, choose to save your settings to file from the “Manage…” button at the bottom (just so we have a copy of your existing settings), and then clicking the “Defaults” button and hitting “Yes” to the warning, so that all settings are reset to the defaults. Then quit Scrivener and restart (not strictly necessary, but just to clear all possible gremlins) and try again. If the bug is gone, then load the settings file you saved to disk via the “Manage…” button again and see if it returns (if so, please send us the settings file).
Next, try the test build, Build 4, that I posted here for laggy scrolling:
(Note that this build will mess up the enabled/disabled state of some buttons, as it was to test some other issues.)
Does the issue persist with that build? (I doubt the build will make a difference, but since it is testing a lag in scrolling, it’s worth checking to see if the lag here has the same cause.)
If all of that doesn’t work, then please try logging into a Guest account on your computer and testing Scrivener’s script mode there. If everything works fine there, then we know it’s something specific in your main account causing the problem.
Ha, well, I wouldn’t call it a weekend off exactly - we drove our daughter 340 miles across the country on Saturday to drop her off at university and then drove back again on Sunday. (Just for context, that’s a long way in Britain; I know it’s probably a daily commute in America. 
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