Easter Sunshine,<br><br>If you want mathematics in Computer Modern / Latin Modern then it should be enough to do nothing (Will, correct me if I'm wrong) because fontspec is designed to revert to the default appearance for mathematics, this is without [no-math] as in TeX Live 2007.. so you might have:<br>
<br><div style="margin-left: 40px;"><span style="font-family: courier new,monospace;">\usepackage{fontspec}</span><br style="font-family: courier new,monospace;"><span style="font-family: courier new,monospace;">\setmainfont{Minion Pro}</span><br>
</div><br>and that's it, without any mention of \setmathrm or other maths commands.<br><br>You however mentioned that your mathematics is set in Minion Pro, which I think is a bit odd because I can't see how you managed to do that. Have you done \usepackage{MinionPro}? What about \usepackage{MnSymbol}? (neither of these packages are in TeX Live 2007, I believe). Send us an example file and we can see exactly how to help.<br>
<br>What happens if you use this (You should get text in Minion Pro and all mathematics in Computer Modern):<br><br><div style="margin-left: 40px;"><span style="font-family: courier new,monospace;">\documentclass{article}</span><br style="font-family: courier new,monospace;">
<span style="font-family: courier new,monospace;">\usepackage{fontspec}</span><br style="font-family: courier new,monospace;"><span style="font-family: courier new,monospace;">\setmainfont{Minion Pro}</span><br style="font-family: courier new,monospace;">
<span style="font-family: courier new,monospace;">\begin{document}</span><br style="font-family: courier new,monospace;"><span style="font-family: courier new,monospace;">some text $some maths$. Latin: $abcd$. Greek: $\alpha\beta\Gamma\Delta$. Operators: $2\times3\circ5$.</span><br style="font-family: courier new,monospace;">
<span style="font-family: courier new,monospace;">\end{document}</span><br></div><br>This will work with the TeX Live 2007 version of fontspec (It should give text and maths letters and numbers in Minion Pro, all other maths symbols like \times and \sqrt{} in Computer Modern):<br>
<br><div style="margin-left: 40px;"><span style="font-family: courier new,monospace;">\documentclass{article}</span><br style="font-family: courier new,monospace;"><br style="font-family: courier new,monospace;"><span style="font-family: courier new,monospace;">\usepackage{fontspec}</span><br style="font-family: courier new,monospace;">
<span style="font-family: courier new,monospace;">\makeatletter\zf@package@euler@loadedtrue\zf@math@lucidatrue</span><br style="font-family: courier new,monospace;"><span style="font-family: courier new,monospace;">\setmainfont{Times New Roman} % You can use Minion Pro</span><br style="font-family: courier new,monospace;">
<span style="font-family: courier new,monospace;">\setmathrm{Times New Roman}</span><br style="font-family: courier new,monospace;"><br style="font-family: courier new,monospace;"><span style="font-family: courier new,monospace;">\newfontfamily\MyFont{Times New Roman}</span><br style="font-family: courier new,monospace;">
<span style="font-family: courier new,monospace;">\DeclareSymbolFont{FontN}{EU1}{\zf@family}{m}{n}</span><br style="font-family: courier new,monospace;"><span style="font-family: courier new,monospace;">\DeclareSymbolFont{FontIt}{EU1}{\zf@family}{m}{it}</span><br style="font-family: courier new,monospace;">
<br style="font-family: courier new,monospace;"><span style="font-family: courier new,monospace;">\catcode`¡=13 % You can choose a different character if this one is not suitable (Do find and replace)</span><br style="font-family: courier new,monospace;">
<span style="font-family: courier new,monospace;">\newcommand¡[1]{\DeclareMathSymbol{#1}{\mathord}{FontN}{`#1}}</span><br style="font-family: courier new,monospace;"><span style="font-family: courier new,monospace;"> ¡0¡1¡2¡3¡4¡5¡6¡7¡8¡9</span><br style="font-family: courier new,monospace;">
<span style="font-family: courier new,monospace;">\newcommand¡[1]{\DeclareMathSymbol{#1}{\mathalpha}{FontIt}{`#1}}</span><br style="font-family: courier new,monospace;"><span style="font-family: courier new,monospace;"> ¡a¡b¡c¡d¡e¡f¡g¡h¡i¡j¡k¡l¡m¡n¡o¡p¡q¡r¡s¡t¡u¡v¡w¡x¡y¡z</span><br style="font-family: courier new,monospace;">
<span style="font-family: courier new,monospace;"> ¡A¡B¡C¡D¡E¡F¡G¡H¡I¡J¡K¡L¡M¡N¡O¡P¡Q¡R¡S¡T¡U¡V¡W¡X¡Y¡Z</span><br style="font-family: courier new,monospace;"><span style="font-family: courier new,monospace;">\newcommand¡[2]{\XeTeXmathcode`#1=0 5`#1\let#2=#1}</span><br style="font-family: courier new,monospace;">
<span style="font-family: courier new,monospace;"> ¡α\alpha¡β\beta¡γ\gamma¡δ\delta¡ε\epsilon¡ζ\zeta¡η\eta¡θ\theta¡ι\iota¡κ\kappa¡λ\lambda</span><br style="font-family: courier new,monospace;"><span style="font-family: courier new,monospace;"> ¡μ\mu¡ν\nu¡ξ\xi¡ο\omicron¡π\pi¡ρ\rho¡σ\sigma¡τ\tau¡υ\upsilon¡φ\phi¡χ\chi¡ψ\psi¡ω\omega</span><br style="font-family: courier new,monospace;">
<span style="font-family: courier new,monospace;"> ¡ς\varsigma</span><br style="font-family: courier new,monospace;"><span style="font-family: courier new,monospace;">\newcommand¡[2]{\XeTeXmathcode`#1=7 4`#1\let#2=#1}</span><br style="font-family: courier new,monospace;">
<span style="font-family: courier new,monospace;"> ¡Α\Alpha¡Β\Beta¡Γ\Gamma¡Δ\Delta¡Ε\Epsilon¡Ζ\Zeta¡Η\Eta¡Θ\Theta¡Ι\Iota¡Κ\Kappa¡Λ\Lambda</span><br style="font-family: courier new,monospace;"><span style="font-family: courier new,monospace;"> ¡Μ\Mu¡Ν\Nu¡Ξ\Xi¡Ο\Omicron¡Π\Pi¡Ρ\Rho¡Σ\Sigma¡Τ\Tau¡Υ\Upsilon¡Φ\Phi¡Χ\Chi¡Ψ\Psi¡Ω\Omega</span><br style="font-family: courier new,monospace;">
<br style="font-family: courier new,monospace;"><span style="font-family: courier new,monospace;">\begin{document}</span><br style="font-family: courier new,monospace;"><span style="font-family: courier new,monospace;">some text $some maths\cos\theta$. Latin: $abcd$. Greek: $\alpha\beta\Gamma\Delta$. Operators: $2\times3\circ5$.</span><br style="font-family: courier new,monospace;">
<span style="font-family: courier new,monospace;">\end{document}</span><br></div><br>In the lines that have \XeTeXmathcode, in this example, font numbers 4 and 5 give Regular and Italic. If you have loaded other fonts (e.g. AMS's), then change these numbers by trial and error until you get Greek (usually capitals is in regular and lower case is in italic).<br>
<br>Downloading the new fontspec.sty from CTAN, and replacing the old one (to use [no-math] option) shouldn't break your TeX Live installation. You can always make a backup of the old fontspec.sty and put it back if needed.<br>
<br>Let us know if this achieves (or doesn't achieve) what you want.<br><br>Andrew<br>