htaccess issues with root htaccess rules?

Hi

Usually I have been messing around with one script per domain but now I have got two scripts on the same domain and am having htacess issues

on mydomain.com I have a script and on mydomain.com/blog I have wordpress.

for the main domain the offending htaccess code seems to be:

Options +FollowSymLinks
RewriteEngine On
RewriteBase /

RewriteCond %{HTTP_HOST} ^mydomain\.com$ [NC]
RewriteRule ^(.*)$ http://www.mydomain.com/$1 [R=301,L]

RewriteCond %{THE_REQUEST} ^.*/index.php [NC]
RewriteRule ^(.*)index.php$ http://www.mydomain.com/$1 [R=301,L]

and when you visit the site at mydomain.com.blog you get this error:

Warning: Unexpected character in input: ‘ in /usr/bin/php5-cgi on line 4009

Warning: Unexpected character in input: ” (ASCII=4) state=1 in /usr/bin/php5-cgi on line 4009

Parse error: syntax error, unexpected ‘$’ in /usr/bin/php5-cgi on line 4009

and the url changes to mydomain.com/cgi-bin/php/blog

Only when I remove the htaccess code on the main domain does wordpress in the subdirectory function correctly.

Anyone know how to get around this problem?

Thanks

B