I have the same problem. Before 3.8.0 all was fine.
Now, "makestaticcache.php -f" does not delete static files if those exists. Why? Is it a bug, or we have to use additional siteaccess with no rewrite riles for static files, when generating static cache?
As temporary solition, I've taken some sources from old EZ version.
Interesting. This was coincidently my first time with eZP 3.8. Which files did you "downgrade" to version 3.7 in order to make it work? Do you also get all the md5-style filenames in your static directory?
I haven't checked whether it completely fixes the problem, but have a look at my patch for bug #6792 at http://ez.no/community/bugs/static_cache_and_old_urls. It should resolve at least the issue of static cache files not getting replaced with new content.
Greetings, Peter
Accessible website starting from eZ publish 3.0 (currently: 4.1.0): http://pluspunkt.at