Unable to read.csv because of special character in file

Colleagues,

I am trying to read a file that contains the ? (mu character).
readLines is succcessful and shows the following:
	"\xb5g/mL\"

read.csv yields the following:

Error in type.convert(data[[i]], as.is = as.is[i], dec = dec,  
na.strings = character(0)) :
 invalid multibyte string at '<b5>g/mL'

using a text editor, i replaced all occurrences of ? (mu) - at which  
point read.csv worked properly.

sessionInfo()

R version 2.8.0 (2008-10-20)
i386-apple-darwin8.11.1

locale:
en_US.UTF-8/en_US.UTF-8/C/C/en_US.UTF-8/en_US.UTF-8

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base

Although my work-around was successful, I am wondering whether there  
is some means to accomplish this without editing the source document:
1.  is it possible to inform R to read the character in its natural  
form?
2.  if not, I could execute readLines, then do a gsub (which did not  
work - any ideas of how to formulate the regular expression would be  
appreciated). then write to a tempfile and read in again (or use a  
textConnection).

Dennis

Dennis Fisher MD
P < (The "P Less Than" Company)
Phone: 1-866-PLessThan (1-866-753-7784)
Fax: 1-415-564-2220
www.PLessThan.com