Old vs. New and LotusXSL

The following code works fine on my local machine running v0_18_2. Any
reason why it would work with the immediate previous version of LotusXSL?

<xsl:variable name="getModuleNumberCurrent">
<xsl:value-of select="PXML/@about"/>
</xsl:variable>
<xsl:variable name="moduleNumberCurrent">
<xsl:value-of select="substring($getModuleNumberCurrent, 11, 1)"/>
</xsl:variable>

I get this error when I run it on my server which is the previous version:

Error! String index out of range: -9 XSL Process was not successful.

Help!

Thanks,

Jon


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