[XeTeX] XeTeX, hyperref, undefined control sequence since MiKTeX update

[Rik Kabel]

I have come across a problem with the combination of XeTeX and hyperref
since a recent update of MiKTeX 2.7 packages. A minimal test file is:
	 \documentclass{letter}
	 \usepackage{hyperref}
	 \begin{document}
	 When\footnote{not \today} in the Course of human events it becomes
necessary for one people to dissolve the political bands which have
connected them with another and to assume among the powers of the earth,
the separate and equal station to which the Laws of Nature and of
Nature's God entitle them, a decent respect to the opinions of mankind
requires that they should declare the causes which impel them to the
separation.
	 \end{document}

The error message is:
   htest.tex(1367): Error: ! Undefined control sequence.
(always referenceing line 1367).

The log shows:
	>This is XeTeX, Version 3.1415926-2.2-0.997 (MiKTeX 2.7) (preloaded
format=xelatex 2008.4.17)  18 APR 2008 10:08
	entering extended mode
	**htest.tex
	(htest.tex
	LaTeX2e <2005/12/01>
	Babel <v3.8j> and hyphenation patterns for english, dumylang,
nohyphenation, ge
	rman, ngerman, french, ancientgreek, latin, loaded.
	("C:\Program Files\MiKTeX 2.7\tex\latex\base\letter.cls"
	Document Class: letter 1999/04/29 v1.2z Standard LaTeX document class
	("C:\Program Files\MiKTeX 2.7\tex\latex\base\size10.clo"
	File: size10.clo 2005/09/16 v1.4f Standard LaTeX file (size option)
	)
	\longindentation=\dimen102
	\indentedwidth=\dimen103
	\labelcount=\count79
	)
	("C:\Program Files\MiKTeX 2.7\tex\latex\hyperref\hyperref.sty"
	Package: hyperref 2008/04/12 v6.77m Hypertext links for LaTeX

	("C:\Program Files\MiKTeX 2.7\tex\latex\graphics\keyval.sty"
	Package: keyval 1999/03/16 v1.13 key=value parser (DPC)
	\KV at toks@=\toks14
	)
	("C:\Program Files\MiKTeX 2.7\tex\latex\oberdiek\hycolor.sty"
	Package: hycolor 2007/04/11 v1.1 Code for color options of
hyperref/bookmark (H
	O)
	)
	\@linkdim=\dimen104
	\Hy at linkcounter=\count80
	\Hy at pagecounter=\count81

	("C:\Program Files\MiKTeX 2.7\tex\latex\hyperref\pd1enc.def"
	File: pd1enc.def 2008/04/12 v6.77m Hyperref: PDFDocEncoding definition (HO)
	)
	("C:\Program Files\MiKTeX 2.7\tex\generic\oberdiek\etexcmds.sty"
	Package: etexcmds 2007/12/12 v1.2 Prefix for e-TeX command names (HO)

	("C:\Program Files\MiKTeX 2.7\tex\generic\oberdiek\infwarerr.sty"
	Package: infwarerr 2007/09/09 v1.2 Providing info/warning/message (HO)
	)
	Package etexcmds Info: Could not find \expanded.
	(etexcmds)             That can mean that you are not using pdfTeX 1.50 or
	(etexcmds)             that some package has redefined \expanded.
	(etexcmds)             In the latter case, load this package earlier.
	)
	! Undefined control sequence.
	l.1367 ...f{\noexpand\UTFviii at four@octets\stringô
							  }%
	The control sequence at the end of the top line
	of your error message was never \def'ed. If you have
	misspelled it (e.g., `\hobx'), type `I' and the correct
	spelling (e.g., `I\hbox'). Otherwise just continue,
	and I'll forget about whatever was undefined.

	("C:\Program Files\MiKTeX 2.7\tex\latex\00miktex\hyperref.cfg"
	File: hyperref.cfg 2002/06/06 v1.2 hyperref configuration of TeXLive
	)
	("C:\Program Files\MiKTeX 2.7\tex\latex\oberdiek\kvoptions.sty"
	Package: kvoptions 2007/10/18 v3.0 Keyval support for LaTeX options (HO)
	)

There is no significant difference when the [xetex] option is provided to
hyperref, nor when [debug] is provided.

When line 2 of the example is removed, the error does not occur.
When pdflatex is used instead of xelatex, the error does not occur.

The problem did not occur with earlier versions of the involved packages
(taken from the log of another document):
	This is XeTeX, Version 3.141592-2.2-0.997 (MiKTeX 2.7) (preloaded
format=xelatex 2008.3.10)  30 MAR 2008 01:01
	entering extended mode
	**quotation.tex
	(quotation.tex
	LaTeX2e <2005/12/01>
	Babel <v3.8h> and hyphenation patterns for english, dumylang,
nohyphenation, ge
	rman, ngerman, french, ancientgreek, latin, loaded.
	("C:\Program Files\MiKTeX 2.7\tex\latex\hyperref\hyperref.sty"
	Package: hyperref 2008/01/09 v6.77i Hypertext links for LaTeX

I cannot reproduce the problem using TeXLive 2007 on Feisty, but I do not
have the same versions of the packages there.

Suggestions?

-- 
Rik    Creating tomorrow's legacy systems today