I still have no solution but I figured out that it has something to do with character encoding.
The first few lines of my rss.php file are the following:
<?php
header("Content-Type:application/xml;charset=UTF-8");
echo '<?xml version="1.0" encoding="UTF-8"?>
';
?>
<rss version="2.0" xmlns:reviews="http://www.chaindlk.com/reviews/">
<channel>
...
I noticed that if I leave it as it is I get this:
built in RSS reader in Safari: NO
Google RSS reader in Safari: YES
NewsGator RSS reader in Safari: NO
built in RSS reader in Firefox: NO
Google RSS reader in Firefox: YES
NewsGator RSS reader in Firefox: NO
If I change the first few lines to this:
<?php
header("Content-Type:application/xml;charset=iso-8859-1");
echo '<?xml version="1.0" encoding="iso-8859-1"?>
';
?>
<rss version="2.0" xmlns:reviews="http://www.chaindlk.com/reviews/">
<channel>
...
then I get these results:
built in RSS reader in Safari: YES
Google RSS reader in Safari: YES
NewsGator RSS reader in Safari: NO
built in RSS reader in Firefox: YES
Google RSS reader in Firefox: YES
NewsGator RSS reader in Firefox: NO
If I remove the character encoding specifications altogether in both the instances then I get this mixed result:
built in RSS reader in Safari: YES
Google RSS reader in Safari: YES
NewsGator RSS reader in Safari: NO
built in RSS reader in Firefox: NO
Google RSS reader in Firefox: YES
NewsGator RSS reader in Firefox: NO
I also tried replacing application/xml with text/xml but nothing changed (I don't know what the difference is).
Any ideas how to interpret this and with what character encoding to go?