[l2h] gray background for some images

[Jean-Pierre Chretien]

[...]

>>$E_{\text{Bayes}}$

$E_{\textrm{Bayes}}$ gives the correct result, and *is* the current correct syntax to get
roman fonts in math.

As for the picture, I always use xfig to do such things, so I don't know
what happens in a picture env.

On Netscape 4.8/Solaris, png transparency is not available, 
so the result may depend upon the browser.

It is good to know also that a bug (IMHO, and ond Ros Moore's also,
but seemingly NOT on the developers') in Mozilla/Firefox turns into a failure
to align inline equations, which are correctly seen
in IE and Konqueror, and others I guess.

I guess also it's possible to correct the css for new documents, but for old ones
you may have to start again the conversion, if you feel like it :-(

-- 
Jean-Pierre