It would be good to reset the last modification time of files used in the cache when that last modification time is in the future. That could automatically solve problems like http://forum.dokuwiki.org/thread/6248
and during the change from summer- to wintertime there are most probably caching problems that could be solved, too.
The basic idea would be to:
- correct files in data/ whenever the timestamp is in the future
- correct DokuWiki core files when the time is more than a few hours in the future
- if that doesn't work display an error message pointing to a FAQ explaining how to manually reset the timestamps (e.g. by reinstalling DokuWiki).
We should however do some tests if time() and the modification time of files is always the same and if not create a reference file somewhere for determining the difference. Perhaps that could also be done as an indexer task in order to not to slow down the cache.