This is what my guess is. I do not know how they talk to each other in detail, but I wanted to share my solution hereby, since it worked for me. When I find out more, I will let you know. I also reported this to Astaro.
Just to avoid everything is lumped together, can you be more precise? What do you see in the logs (e.g. http_access.log, contentfilter.log, squid.log), that refers to it?
