Test durations greater than 59 seconds are shown as 0ms. This occurs often for
data driven tests.

possible solution (not nice but working - maybe you know a better one):
...
<xsl:variable name="duration_seconds"
select="number(substring-after(substring-after(@duration, ':'), ':'))"/>
<xsl:variable name="duration_minutes"
select="number(substring-before(substring-after(@duration, ':'), ':'))"/>
<xsl:variable name="duration_hours" select="number(substring-before(@duration,
':'))"/>
...
time="{$duration_seconds + $duration_minutes * 60 + $duration_hours * 60 * 60}