Comment 1 for bug 1292421

It seems that the Problem is the Avira Webgate Proxy which is downloading the files first than check them and send it to Ubuntu after that. If I wait some times for the downloading the vira proxy do (calculating the time for the download is not easy) and then do an apt-get upgrade again, its working. If I wait to long the proxy removes the File and have to download it again and apt-get gets an error again too.