I used Turck and not had these error messages, but with the latest Moodle (1.2 and above) the text filtering module (auto-linking, etc) causes part pages to be displayed if the cache is on.
We've got a fast machine and it doesn't seem to mind too much, but some things (particulaly enrolling on a course) seem to take significantly longer.
(I've not upgraded to Apache 2 yet by the way).