[XeTeX] Problem changing default fonts

[Will Robertson]

On 2010-09-27 02:14:03 +0930, Drébon 
<bedouin_drebon at hotmail.com> said:

> \usepackage{pxfonts}
> \usepackage{txfonts}
> \usepackage[osf,sc]{mathpazo}

You just changed the math/text font three times...

> \usepackage[scaled=0.85]{beramono}
> \usepackage[euler-digits]{eulervm}
> \usepackage{helvet}

...and this is the second change of the sans serif font.
I suggest culling your preamble a little.

> The first group of packages are used to change the fonts. But if I use
> the xltxtra package, they have no effect.
> 
> On the other hand, if I do not use xltxtra package, the œ character is
> not accepted and thus 'cœu' becomes 'ceur'...

If you're only using UTF8 for Latin input text, you can use pdfLaTeX with

    \usepackage[utf8]{inputenc}

But if you insist on using XeLaTeX, you should probably go the whole 
hog and load a Unicode font. Try TeX Gyre Pagella as a replacement for 
mathpazo as your text font. Something like

\setmainfont[
  Extension=.otf,
  UprightFont=*-regular,
  ItalicFont=*-italic,
  BoldFont=*-bold,
  BoldItalicFont=*-bolditalic,
]{texgyrepagella}

Cheers,
Will