XML entities are resolved before the XPath parser sets to work, so the XPath parser sees
' Above message MUST be sent to when a person's vehicle is '
which is not a valid string literal. In XPath 2 you can write
' Above message MUST be sent to when a person''s vehicle is '
In XPath 1.0 there's no way of escaping the string delimiter. But you can use
xsl:value-of select='" Above message MUST be sent to when a person's vehicle is "'
Michael Kay
http://www.saxonica.com/
Author, XSLT Programmer's Reference and XPath 2.0 Programmer's Reference