[Orgmode] Strange results of special symbol inside brackets in PDF output

[Keith]

Dear all,

Well..., I am just new to both emacs and org-mode and trying to get used 
to it :-)

I noticed something strange and I think it's might be a bug converting 
to tex file. I've been trying to put a special symbol inside a bracket, e.g.

  air temperature (degree Celsius)

and the symbol should look like ^{\circ}C in org file. It works well if 
it is standalone. However, when I put the brackets out of it, say 
(^{\circ}C), the pdf output looks bizarre. I have checked the tex output 
and the converting results from orgmode file are

  ^{\circ}C   -->   $^{\circ}$C
  (^{\circ}C) -->   (^\{\circ}C)

Keith