Forgive my noobishness, I'm not sure I can help but I'd like to
understand your dilemma, as I do a simpler version of what you
propose.

Everytime you get a new customer, are you re-writing the original XML
file to include their information,

including a unique key?

--
jvrn nettingsmeier

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http://spunk.dnsalias.org
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if you are a free (as in "free speech") software developer
and you happen to be travelling near my home, drop me a line
and come round for a free (as in "free beer") beer. :-D