[xsl] Group problem with blank elements

["Ed Yau" <eyau@xxxxxxxxxxxxxxx>]

Hiya,

Having loads of trouble with this.  On the face of it a really easy
problem.
I have a bunch of elements like so:

<statement-message>Your account is now seriously in arrears.
To</statement-message>

<statement-message>avoid further action a payment of</statement-message>

<statement-message>$82.00 is required immediately.
Any</statement-message>

<statement-message>purchases will now be declined.</statement-message>

<statement-message>
</statement-message>

<statement-message>  More text </statement-message>

<statement-message>
</statement-message>

<statement-message>
</statement-message>

<statement-message>
</statement-message>

I want to strip out the empty tags and merge adjacent elements as
follows:

<statement-message> Your account is now seriously in arrears. To avoid
further action a payment of
82.00 is required immediately. Any purchases will now be
declined.</statement-message>

<statement-message>  More text </statement-message>

My code at the moment is:
<xsl:for-each-group select="statement-message"
group-ending-with="statement-message[string-length(normalize-space(follo
wing-sibling::statement-message[1]))=0]">
	<statement-message>
		<xsl:value-of select="."/>
	</statement-message>
</xsl:for-each-group>

My understanding of this is that it should start grouping from the 1st
statement message, with the groups ending as soon as an empty element is
reached.  The empty tags at the end would still be there, but at least
it should do the merge.  However, the result looks like:

     <statement-message>Your account is now seriously in arrears.
To</statement-message>
     <statement-message>
     </statement-message>
     <statement-message>  More text </statement-message>
     <statement-message>
     </statement-message>
     <statement-message>
     </statement-message>
     <statement-message>
     </statement-message>

So where am I going wrong?

Ed