When Smarty recompiles the files in templates_c, they retain the mtime of the originating template files,
which is typically the exact same mtime they had before being cleared. Then the op-code accelerator sees the
same timestamp as before and does not refresh the op-code files.
Latest "Turck MMCache" checks for filesize and inode number (if applicable) too, so the situation is unlikely to appear.
On the other hand, if the source template has the same mtime, it was not changed, and need not to be re-op-cached.
Konstantin Pelepelin