Strange characters appearing in wordpress (using Twenty Eleven theme)

Hi

Whenever i’m adding an Apostrophe to a wordpress post I create

‘

Its saving as a strange set of characters

a€?

I’ve used wordpress many times, never encountered this problem

i’ve uninstalled every single plugin, and the problem remains

I read somewhere to comment out these lines in wp-config.php but it doesnt help for new posts

/** Database Charset to use in creating database tables. */
//define(‘DB_CHARSET’, ‘utf8’);

/** The Database Collate type. Don’t change this if in doubt. */
//define(‘DB_COLLATE’, ”);

Can someone help me? DO need to set the Charset to override somewhere? HOw??

Thank you so much