R help - Feb 2011 - How to source() a .R file which was saved using UTF-8 encoding on Windows?

Dear all,

[Note: This was originally posted over at Stack Overflow, but it was
suggested that the problem may be an error in R on Windows, so I have
cross posted over here too. ref: http://goo.gl/pd54D)

The following, when copied and pasted directly into R works fine:
> character_test <- function() print("R??????GNU
S????????????????????????????????????...")
> character_test()
[1] "R??????GNU S??????????????,???????,?????????????..."

However, if I make a file called character_test.R containing the EXACT
SAME code, save it in UTF-8 encoding (so as to retain the special
Chinese characters), then when I source() it in R, I get the following
error:
> source(file="C:\\Users\\Tony\\Desktop\\character_test.R",
encoding = "UTF-8")
Error in source(file = "C:\\Users\\Tony\\Desktop\\character_test.R",
encoding = "utf-8") :
  C:\Users\Tony\Desktop\character_test.R:3:0: unexpected end of input
1: character.test <- function() print("R
2:
  ^
In addition: Warning message:
In source(file = "C:\\Users\\Tony\\Desktop\\character_test.R",
encoding = "UTF-8") :
  invalid input found on input connection 'C:\Users\Tony\Desktop
\character_test.R'


Any help you can offer in solving and helping me to understand what is
going on here would be much appreciated.

Best,
Tony Breyal


### Session information ###
> sessionInfo() # Windows 7 Pro x64
R version 2.12.1 (2010-12-16)
Platform: x86_64-pc-mingw32/x64 (64-bit)

locale:
[1] LC_COLLATE=English_United Kingdom.1252
[2] LC_CTYPE=English_United Kingdom.1252
[3] LC_MONETARY=English_United Kingdom.1252
[4] LC_NUMERIC=C
[5] LC_TIME=English_United Kingdom.1252

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

loaded via a namespace (and not attached):
[1] tools_2.12.1

and
> l10n_info()
$MBCS
[1] FALSE

$`UTF-8`
[1] FALSE

$`Latin-1`
[1] TRUE

$codepage
[1] 1252