That is odd. Deleting and uploading a script should take affect immediately. It could be a concurrency issues with the bot being accessed while the script is being compiled. If you narrow down when it occurs, please send us the details.
The clear cache button should resolve the issue. It will clear to bot memory so it will reload from the database.
Everything in the bot's brain including its scripts are stored in its own database. As the bot is accessed its data gets loaded into a cache (like an object database). The Clear Cache button clears the cache, so it will reload everything from the database.