welcome to the forum.
I've "upped" from 5.5->8, 7->8 and 5.5->9 and haven't had the issue you describe.
I'm responding only from a practical "make it work" sense to say that if you cannot "turn Preview Mode off", you can certainly "Turn Browse Mode on" at the end of your script.
Depending heavily on the number and length of your scripts, you might also want to try rewriting one/all in FMP9 to verify whether it's an upgrade quirk or a scripting issue. If they work perfectly when built in FMP9 then it's the upgrade. Of course this depends on how many/how big we're talking about for the scripts...your call.
Let us know how it goes...
Thank you for your post.
Place a "Halt Script" step at a different point in your script just to make sure everything is working as expected. This may provide a clue where it is turning into Preview Mode. Assuming the script is corrupt, remove the offending steps and add them again.
The suggestion by Ninja is excellent (Thank you!). That is, add the script step:
Enter Browse Mode 
... at the end of the script.
That is a good idea to turn browser mode on. That will be the easiest and fastest for now. I have a lot of scripts there. And they all have the same problem.
After I finish taxes, then I will go back and redo all the scripts.
Well, i guess I never got around to it. I am now using FM Pro 12 and back at taxes. And I just noticed the windows are still in preview mode. So maybe I will get to it this year. But now I will post my other questions about scripts.
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