g1smd - 8:33 pm on Oct 12, 2012 (gmt 0)

If internal links begin with a leading slash (or begin with protocol and hostname) then you have "fixed" the problem.

Google will request the duff URLs forever. Make sure they return 404 and then move on. The frequency of requests will diminish over time.

The * in ^([^/]*)/([^/]*)/([^/]*)/([^/]*)\.html$ allows a request for example.com////.html to be considered valid and be rewritten (with blank parameter values passed to the PHP script). The * should be replaced with a + in each case.

The final [^/] in each rule should be [^/.] as you're looking to stop at the period before the extension, no longer looking only for folder slashes.