I think Avast! is the culprit because I also use the
portable version of
Iron Chrome 15 that does not show this error. If I correctly understand the way Avast!'s transparent proxy works, it cannot "see" traffic coming from Iron Chrome because it doesn't recognize it as a browser process.
I don't have any other software installed that interacts with the network on this level. Also there are older threads in this forum where the same problem occured for Opera users and Avast! 5.x versions, e.g.:
http://forum.avast.com/index.php?topic=68494.0In this thread "sded" writes:
"The pipelining support seems to fix the Opera 11 stalls, but now I am getting a lot of "connection closed by remote server" messages from Opera 11. Need to be very slow and methodical in clicking, and sometimes backspace and repeat to make it all work. So not quite there yet."
This is exactly what I'm experiencing.