This gets even more problematic if you support third party developers/modules as they have to follow the same rules as well. Head problems off at the pass by using the Solar_Cache prefix config. This bit of code would be placed as soon you "identify" the site in question and get some sort of unique id for that site.
All it takes is creating a Solar_Cache object (set into the Solar_Registry object) with the prefix for any and all scripts to pull out and use. This can even be used with the Solar models to cache data pulled from the database automatically.