The Streaming works fine now. I've set a custom-security-level in IE and allowed some not recommended scripts. Then the IE works well. After that I set the security-level to standard (medium-high), but the streaming works furthermore...? But only if I comment line 192. in xajax.inc.js
Another Problem occurs if I test it in Safari 3.5 / 3.5 Nightbuild. In this Browser there comes a warning, that the comet-streaming is disabled in Safari. (you'll see it on the screenshot) On your website you write, that comet is available in safari 3???