I've been using this code to 301 redirect WP pages like this one: mysite.co.uk/?page_id=12983 to: mysite.co.uk/nicepagetitle/
RewriteCond %{QUERY_STRING} !^page_id=$ RewriteRule .* http://mysite.co.uk%{REQUEST_URI}? [R=301,L]
I'm not sure if this is correct and what's more Google is still showing these pages: mysite.co.uk/?page_id=xxx in my Webmaster tools under HTML suggestions.
I will appreciate if you help me with this issue.