File Type Association not being saved on Native Installer

I currently have an Air Native Installer for an Extended Desktop application what doesn’t always associate the file extension stored in the –app.mxml file.

Here is the –app.xml section in question:

      <filename>programName</filename>

      <fileTypes>

            <fileType>

                  <contentType>text/plain</contentType>

                  <description> programName Network File</description>

                  <extension>nle</extension>

                  <icon>

                        <image128x128>icons/nle_icon_128.png</image128x128>

                        <image48x48>icons/nle_icon_48.png</image48x48>

                        <image32x32>icons/nle_icon_32.png</image32x32>

                        <image16x16>icons/nle_icon_16.png</image16x16>

                  </icon>

                  <name>programName.nle</name>

            </fileType>

      </fileTypes>

Am I missing some value or have setup one of the above elements incorrectly?

The native installer is being created with Flash Builder 4.0.1 using the Flex SDK version 4.1 on a Windows7 machine.

There doesn’t seem to be any rhyme or reason to what OS (WinXP, Windows7) is having trouble with the installer, sum update the file type list other do not and need to be associated manually which is not the desired method.