Hello Hans,

I've updated original TeXLive2007 distribution to the latest cont-tmf beta, by copying \web2c into TeXLive2007\texmf folder and every other stuff into TeXLive2007\texmf-dist folder. Then I rebuilded the format files for both context and xetex (texexec --make en, then  texexec --xtx --make en). Now  xetex doesn't see the font that it previously did. The setting

\definetypeface[myface][rm][Xserif][Adobe Caslon Pro] 

now gives

This is XeTeXk, Version 3.141592-2.2-0.996 (Web2C 7.5.6) (format=cont-en 2007.6.18)  18 JUN 2007 20:20

entering extended mode

\write18 enabled.

 %&-line parsing enabled.

 (WARNING: translate-file "natural.tcx" ignored)

**FMHelp.tex \emergencyend

(./FMHelp.tex

ConTeXt  ver: 2007.06.06 09:53 MKII  fmt: 2007.6.18  int: english/english

...

! Font \*myface212ptrmtfrm*:='"mapping=tex-text at 12.0pt"' not loadable: insta

lled font not found.

<to be read again> 

                   \relax 

\xxdododefinefont ...tspec {#4}\newfontidentifier 

                                                  \let \localrelativefontsiz...

\fontstrategy ...me \fontclass #2#3#4#5\endcsname 

                                                  \tryingfontfalse \fi 

<inserted text> ...yle \fontalternative \fontsize 

                                                  \fi \iftryingfont \fontstr...

\synchronizefont ...strategy \the \fontstrategies 

                                                  \relax \fi \iftryingfont \...

<argument> \getvalue {\@style@ \fontstyle }

                                           \edef \fontstyle {\fontstyle }\if...

...

Best,

Vyatcheslav