When I visit the web-page http://www.ol-in-berlin.de, the random image on the left (http://www.ol-in-berlin.de/module/startseite_bild.php) is not displayed correctly. It happens with Firefox 16 as well as with Chrome 22 and Internet Explorer 9 under Windows 7 Home Premium with all system updates.
For example, when the image should be
instead I get:
Firebug shows the following information:
HTTP/1.1 200 OK Date: Sat, 03 Nov 2012 16:45:22 GMT Server: Apache X-Powered-By: PHP/5.2.17 Content-Disposition: attachment; filename="olb_start0067.JPG" Keep-Alive: timeout=2, max=199 Connection: Keep-Alive Transfer-Encoding: chunked Content-Type: image/jpeg
and it says it received 4467 bytes in the body and 4738 bytes total. When I now look into wireshark, it lists the image transfer correctly.
21 Reassembled TCP Segments (29375 bytes): #7777(1460), ...
Hypertext Transfer Protocol it lists a chunked response with 6 chunks of 4096 Bytes and one of 4467 Bytes. So it seems like in this case all but the last one get lost somewhere on the way to the browser.
In other tries, there are some more chunks displayed, but in most cases some are missing.
It seems like disabling "Kaspersky Internet Security" made the problem disappear. Of course this is not a permanent solution.