Hi Jan,

The problem is in your xsl:if test.

<xsl:if test="@lang=$selectedLanguage or 
  (not(following-sibling[@lang=$selectedLanguage]) and
  not(preceding-sibling[@lang=$selectedLanguage]) and
  @lang=$defaultLanguage)">

add "::*" between the axis name and predicate:

<xsl:if test="@lang=$selectedLanguage or 
  (not(following-sibling::*[@lang=$selectedLanguage]) and
  not(preceding-sibling::*[@lang=$selectedLanguage]) and
  @lang=$defaultLanguage)">

But you can combine the second and third test. Instead
of checking the following and preceding siblings, you can
as well check them all:

<xsl:if test="@lang=$selectedLanguage or 
  (not(parent::*/*[@lang=$selectedLanguage]) and
  @lang=$defaultLanguage)">

Hope this helps,
Anton