Hi Andi,
thank you for your reply.
More details... well, technically all is said. It's just a plain, normal Apache server with the usual stuff. I work in a simple way with it: Writing down knowledge on different issues, previewing and then saving them. Dokuwiki behaves weiredly slow recently on preview and save. Take a look at
http://www.rot65.de/dokuwiki (it's all in German, though)
In the beginning Dokuwiki was amazingly fast. It's not that fast anymore although nothing has been changed either in dokuwiki's configuration or the server's. That's why I wonder whether there is a possibility that dokuwiki becomes slower the more data is collected with it (e.g. stuff written).
On my Mac, just today, dokuwiki functions normally again. The local server here too is a plain simple Apache thing with the ususal settings and so on. Problems occured too on preview and save and I wonder why it functions normally today.
Sorry, that I can't offer more, since these are just my observations, and I thought you might know the cause.
Regards,
spida