I agreed with Brenden. And want to say more. You can get similar problem like as "Kentico hangs" when IIS application pool process out from memory. In this case app pool should be restarted by IIS. Kentico doesn't know nothing about this and still to wait answer from previous process. But IIS has new already.
So, you can see that Kentico "hangs".
Try to check IIS app pool resources for your Kentico hosting, please.