[OS X TeX] Strange error

[Alain Schremmer]

or, at least, an error I don't understand.

Yesterday, I started to get the following error:

When I try to use align, say from the LaTeX panel, I get the  
following console error:

	! Improper \halign inside $$'s.
	<recently read> \halign

	l.11 \end{align}

	?

1) I have reduced to the following minimal example:

		\documentclass[11pt]{book}
		\usepackage{lmodern}
		\usepackage{amsmath}
		\usepackage{fink}
		
		\begin{document}
			\begin{align}
	 		  1 &= 2  \\
			   3 &=  4
			\end{align}
		\end{document}

- If I comment out
	\usepackage{lmodern}
or
	\usepackage{fink}
LaTeX typesets the minimal file.

- If not, a return carriage in the console lets LaTeX typeset 1=2 and  
3=4 properly aligned. Here is the end of the console log:

	1{/usr/local/gwTeX/texmf.local/fonts/map/pdftex/updmap/pdftex.map}]
	(./Untitled.aux) ){/usr/local/gwTeX/texmf.texlive/fonts/enc/dvips/lm/ 
lm-rm.enc}
	</usr/local/gwTeX/texmf.texlive/fonts/type1/public/lm/lmr10.pfb>
	Output written on Untitled.pdf (1 page, 17921 bytes).
	Transcript written on Untitled.log.

2) What makes it really strange is that:
-- it just started even though, to my knowledge, my installation and  
my preamble have not changed for several months (I am still on 10.4.9) 
-- any and all the align that I used in the magnum opus still typeset  
without the console squawking but any new one brings up the  
abovementioned error message. 
-- if I copy-paste the above align in any of the chapters that used  
to typeset without problem they immediately cease to work. If I  
comment the pasted align out, the chapters work again.
-- if I copy-paste an align that works, it doesn't work any more
-- commenting out lmodern does not help in the magnum opus and I  
can't afford not to use the fink package.

I have no idea what's going on (I couldn't even find halign in the  
companion 2ed and from
	http://www.cam.ac.uk/cs/docs/leaflets/u36/
  I get the feeling that it is a tex command anyhow) and would very  
much appreciate any explanation/help.

Regards
--schremmer