Resource types

Hi,

the fault is as strange as the title is:

Some of the users has problems to view the complete List of files and folders (/mod/resource/view.php). They just do not appear in the list. If they switch to "edit files" (/files/index.php) they appear suddenly.

I have no clue how to find the error.

Some hints:

The ICT-Team of the user's university did some research:

The conclusions are as follows:
- the problem is not in the browser-software (Internet Explorer), as the same problem occurs when using Firefox
- the problem is not in the internet safety settings of the software or the server, as the problem does not occur with other websites
- the problem appears to result from the communication between the pc and moodle; when opening the E-library from a 'fresh' pc, almost all folders and files in the E-library are visible!

The file owners and permissions do not differ from files the user sees.

I use Moodle 1.8.6+

I appreciate any hint. Thank you!