As we are using variables from the apache environment to decide
redirections with mod_rewrite, the accelerator is giving us a hard time.
We found out, that the http reverse proxy changes values of the apache
environment to the accelerator name and therefore to a static value.
The affected values are ...
... for apache environment: HTTP_HOST, SERVER_SIGNATURE, SERVER_NAME
... in the HTTP header: Host

Using https these values remain unmodified and everything works fine.
At this point we do not see any sense in this behaviour and therefore
assume this to be a bug, but maybe there is a way to control this. Can
someone provide a solution?