palettes of icons in Google Earth (Mac) - macos

Question

(Cross posted from the GE support groups - now defunct?)
Having trouble using the gs:x extensions to use palettes of icons in an icon
group.
I have loaded the appropriate xmlns:gx="http://www.google.com/kml/ext/2.2"
into the kml header but get the message "Unknown type gs:x
on my Macintosh under GE Google Earth 6.0.3.2197
I suspect this has not been implemented on the Mac version - anybody
with experience on this?
Final code was as follows and it fails on the first gx:s line.
It also fails in the same way if I use the now deprecated x (rather than gx:x)
Also, as shown it follows the kml documentation but I think all terminating terms should be of the form /gx:x rather than gx:x/
as shown in the KML reference. Making that change does not help as it never gets to that point anyway.
The header was copied from a GE placemark copied and pasted into the
editor.
Any help appreciated.
Bob J.
<?xml version="1.0" encoding="UTF-8"?>
<kml xmlns="http://www.opengis.net/kml/2.2"
xmlns:gx="http://www.google.com/kml/ext/2.2"
xmlns:kml="http://www.opengis.net/kml/2.2"
xmlns:atom="http://www.w3.org/2005/Atom">
<Document>
<StyleMap id="s_Ic_SP">
<Pair><key>normal</key><styleUrl>#sn_Ic_SP</styleUrl></Pair>
<Pair><key>highlight</key><styleUrl>#sh_Ic_SP</styleUrl></Pair>
</StyleMap>
<Style id="sn_Ic_SP">
<IconStyle>
<scale>1.8</scale>
<Icon>
<href>Icons/Traps.png</href>
<gx:x>0<gx:x/><gx:y>128<gx:y/> <gx:w>64<gx:w/><gx:h>64<gx:h/>
</Icon>
<hotSpot x="32" y="1" xunits="pixels" yunits="pixels"/>
</IconStyle>
<BalloonStyle>
<displayMode>default</displayMode><bgColor>ff00d0ff</bgColor>
<text><![CDATA[<font face="Comic Sans MS" /><table
bgcolor="#ff8000" cellspacing="3" width="160">
<tr bgcolor="#ffff80"><td><b>Sponsor $[name]</b><br/><br/>$
[description]</td></tr></table>]]></text>
</BalloonStyle>
<LabelStyle>
<scale>0.9</scale><color>ff00ffff</color>
</LabelStyle>
<LineStyle><color>ff00ffff</color><width>2.0</width></LineStyle>
<ListStyle>
<ItemIcon>
<href>Icons/Traps.png</href>
<gx:x>0<gx:x/><gx:y>128<gx:y/> <gx:w>64<gx:w/><gx:h>64<gx:h/>
</ItemIcon>
</ListStyle>
</Style>
etc.

Answer 1

Oooops
Seems my problem was a syntax problem
The gx:x set do work correctly. However, they are not operational inside the ItemIcon group as shown in my example. In fact they are ignored in that group.
Thanks for your tolerance of my stupidity
Bob J.