Massive problems with caching and login

Hi everybody,

unfortunatelly I have massive problems with logging in since months and I can´t get them solved. It seems to me like it is a caching-problem, but even after deactivating all caching it doesn´t work.

Here is a short summary:
Users very often get the "security-token"-message when they try to log in. I guess this is because of a cached cookie, but i tried it with the internal cache, with JotCache and with turning all caching off ... it does not get solved. In the moment I have all caching turned off and all caching-plugins deactivated ... the problem still stays.

In addition to that, some pages seem to still get cached. When I log out for example, the page doesen´t change. I click on "log out" on the front-page, I get no error-message but the page still says as it would be when logged in. Only after reloading the page, the "outlogged" frontpage is shown.

Then again, when I deactivate some modules and load the page, the modules are still shown. When I delete all cache in the backend, the modules will also disappear in the frontend. But ... all caching is deactivated. I don´t understand how something could be cached when all cache is turned off.

I tried to nail it down somewhere, but I can´t find any component or extension responsible for that issue. The onliest thing I see is .... this whole issue was not happening before I installed EasySocial. So I hope ... maybe you have any Idea how this can be solved ... ?

All the best, Julian!