[OS X TeX] Greek in the table of contents

[Richard Seguin]

I have a greek letter in several section headers (specifically, \beta,  
used to designate the Stone-Cech compactification, i.e.,  $\beta X$).  
It appears as intended in the table of contents within the document,  
but the letter is completely dropped in the sidebar table of contents  
as displayed by Preview, TeXShop, and Skim, completely changing the  
intended meaning. I thought that this used to work OK. Does this also  
happen with Adobe Reader? I don't have it and hesitate to install it.

I suppose that I could drop $\beta X$ from the section header, but it  
would be at the expense of vagueness.

Richard Séguin