They suggest some other methods, but as far as I can tell they're actually not much better than turning prefetch off. Looks like the performance hit of disabling prefetch is about 3% so it's probably worth dropping it and getting the better accuracy.
Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
There's an article by ST on it here: http://www.st.com/web/en/resource/technical/document/application_note/DM00050879.pdf
They suggest some other methods, but as far as I can tell they're actually not much better than turning prefetch off. Looks like the performance hit of disabling prefetch is about 3% so it's probably worth dropping it and getting the better accuracy.