Thanks for all the suggestions.
I now understand what the "issue" with Chrome 22.0 is and it is easily solved.
Hopefully this information will help somebody else in the future.
If you add the line
Content-Length: "length of data content in bytes"
in the HTTP response header, the byte length of the XML file MUST BE ABSOLUTELY CORRECT or Chrome rejects the xml file with a script error
NETWORK_ERROR: XMLHttpRequest Exception 101
The 101 error is associated with Chrome file access permissions and is completely misleading in this case. It is a wrong Content-Length value which causes the error.
IE 9, FireFox and Safari only complain if the Content-Length value is not larger than the file. The value does not have to be correct.
I have also seen that Chrome only wants the Content-Length to be accurate for XML files. It does not care about .htm, .js etc.
The fix is easy.
Don't put the Content-Length in the HTTP header at all. IE 9, FIREFOX 16.0.1 AND Sarafi 5.1.7 browsers don't care and nor does Chrome 22. So far I haven't found any situation where the Content-Length has to be in the HTTP header.