Filemanager loading really slowly

[sueshi]

Using PS 1.6.1 for nearly 3 years without any problem, but now something weird occurs: When editing cms page and inserting image from filemanager I have to wait up to 20 seconds till the content of filemanager is loaded. First I thought there must be some js or php file missing, but accidentally I realized that it takes only such a long time. Can the size of the content be a problem? I can´t believe this because another customer has many more fotos and some with rather high resolution and is not facing this problem.