[XeTeX] xetex on mac 10.4 with fink tetex distribution; cmr fonts not found

[Robert Felty]

I have been using latex for some time now with much pleasure. I just  
recently discovered xetex, and was quite pleased with the ability to  
use additional fonts on my computer. However, when trying to compile  
the xetex-sample2e.tex file provided with the xetex distribution, I  
get errors saying that it cannot several of the computer modern fonts  
needed to display math, e.g.
*** font cmsy7 not found in psfonts.map or host system; will  
substitute Helvetica glyphs

*** font cmex10 not found in psfonts.map or host system; will  
substitute Helvetica glyphs

I tried running texhash and updmap[-sys] and this did not seem to  
help. Sure enough, when looking at my psfonts.map file, there is  
nothing about computer modern fonts. I looked at some other  
psfonts.map on one of my university's linux servers, and there were  
all sorts of computer modern font mappings in the file. I tried  
adding some of these to my own file in ~/.texmf-var/fonts/map/dvips/ 
updmap/psfonts.map such as this
cmr10 CMR10 <cmr10.pfb
cmmi10 CMMI10 <cmmi10.pfb

Then when running xelatex I got the following warnings:
WARNING: Type1 font data returned by OFAStreamPSDownload isn't in the  
correct format required by the Adobe Type 1 Font Format specification.

although it seems that the glyphs show up fine in the pdf.

I don't seem to have any such warning using latex > dvips > ps2pdf

I racked my brain and read as many help files, FAQs and forum posts  
as possible, but I am still stumped. Your help would be much  
appreciated.

Robert