Can you show a screenshot of the message when you try to save to the SD for the first time on a given app? It sounds like it's asking you to set a default, rather than asking you to set a permission. To clear that default, check the app's settings to see if there is an option there to select the default storage location. If not, then try going to Settings>Apps, tap the Menu button, and the Reset App Preferences (which will clear all app defaults, as well as re-enable any disabled app).
I'm not sure which App Ops is the best one to use, sorry. I'd probably go with the one that has the most downloads, but read through a bunch of the reviews for each app first.