[TYPO3-dev] Weird cache problem with FAL and BE-User

[Rainer Becker]

I have some article records containing download files (FAL). I extended table sys_file_reference with a field "thumbnail" (classic file selection, no FAL).

In a certain order of page requests of the single article view with extbase the thumbnail gets lost in the frontend.

Request order 1:
- clear t3 cache
- request by browser, which is *not* logged in t3 => thumbnail is shown
- request by browser, which is *not* logged in t3 => thumbnail is shown
- request by browser, which is *not* logged in t3 => thumbnail is shown

Request order 2:
- clear t3 cache
- request by browser, which *is* logged in t3 => thumbnail is shown
- request by browser, which is *not* logged in t3 => thumbnail is shown
- request by browser, which is *not* logged in t3 => thumbnail is *not* shown and will never be shown till cache reset

This seems to be a cache related issue to me. 
Every hint or idea is much appreciated...