loading RMySQL - location of MySQL install

I am having trouble loading RMySQL after installing it. ?I have looked at
archived r-help files and it seems many people have had issues, but I didn't
find my specific issue. ?I also went to the webpage at Vanderbilt
(http://biostat.mc.vanderbilt.edu/wiki/Main/RMySQL) and followed the
instructions as best I understood them:

? ?- I created a file called Renviron.site under "etc" in the R folder. ?In
it, I tried to put a pointer to where MySQL is.
? ? ? ?I tried:
? ? ? ? ? ?- MYSQL_HOME=C:/PROGRA~1/MySQL/MYSQL~Server~5.5/
? ? ? ? ? ?- MYSQL_HOME=C:/PROGRA~1/MySQL/MYSQLS~5.5/bin
? ? ? ? ? ? ?(which are guesses at how this should be written from the
example on the webpage.)
? ? ? ? ? ?- MYSQL_HOME=C:/Program Files/MySQL/MySQL Server 5.5
? ? ? ? ? ? ?(the actual location; n.b. adding "\bin" yields the location of
the mysql.exe file)
? ?- I then re-start R and attempt to load the package.
? ?- I get the following error messages:

Loading required package: DBI
Error : MYSQL_HOME was set but does not point to a directory
Error : .onLoad failed in 'loadNamespace' for 'RMySQL'
Error: package/namespace load failed for 'RMySQL'

Does anyone know how to write this so that it does point to the directory
properly?Or, what else might be the problem?

Thanks,
Jeff

PS, I am running windows XP media edition and R 2.10.1, if that matters.