The Jackrabbit Repository Classloader had an issue with accessing class path resources of type nt:file whose jcr:content child nodes were not of type nt:resource. This notably caused the JSP Compiler to unneccessairily compile JSP scripts uploaded through WebDAV over and over again, because the Sling WebDAV component being based on Jackrabbit Simple WebDAV creates the jcr:content nodes as nt:unstructured.
JCR-1749 for a full description.
Currently jackrabbit-classloader 1.4.1 is being voted on for release in the Jackrabbit Dev list. As soon as the vote passes, the Sling jcr/classloader module should be upgraded to the released jackrabbit-classloader module.