[XeTeX] making a format file of ConTeXt using XeTeX

[Dalyoung]

Dear Jonathan and Hans,

Thanks for XeTeX and the file, "syst-xtx.fmt".
After replacing the file with the new one, I am able to make a format 
file.
By the way, the new format file's name is also cont-en.fmt.
I have tested some files under the new installation.

General LaTeX and ConTeXt worked fine, but xelatex and xe-context 
worked with some font error messages as follows even though they worked 
fine before;

<xelatex hoefler-test.tex>
(see the transcript file for additional information)

*** font activation failed (status=0): cmtt10.pfb

*** font cmtt10 (CMTT10: file 'cmtt10.pfb') not found

*** font cmtt10 (cmtt10.pfb) not found, will substitute Helvetica glyphs

*** font activation failed (status=0): cmr10.pfb

*** font cmr10 (CMR10: file 'cmr10.pfb') not found

*** font cmr10 (cmr10.pfb) not found, will substitute Helvetica glyphs
Output written on hoefler-test.pdf (1 page).
Transcript written on hoefler-test.log.

<xecontext>
  TeXUtil 9.0.0 - ConTeXt / PRAGMA ADE 1992-2004

                 action : processing commands, lists and registers
                 option : sorting IJ under Y
                 option : converting high ASCII values
             input file : celtic1.tui
            output file : celtic1.tuo
        passed commands : 44
          remapped keys : 0
       register entries : 0 -> 0 entries 0 references
        synonym entries : 0 -> 0 entries
         embedded files : 1

*** font activation failed (status=0): cmsy10.pfb

*** font cmsy10 (CMSY10: file 'cmsy10.pfb') not found

*** font cmsy10 (cmsy10.pfb) not found, will substitute Helvetica glyphs

*** font activation failed (status=0): cmmi10.pfb

*** font cmmi10 (CMMI10: file 'cmmi10.pfb') not found

*** font cmmi10 (cmmi10.pfb) not found, will substitute Helvetica glyphs

         total run time : 21 seconds


I located font file cmr7.pfb, cmsy10.pfb,... in 
texmf.tetex/fonts/type1/bluesky/cm/.

What did I wrong and how can I remove this kind of errors?

Thank again.

Dalyoung