Author & Blog permalinks

Hi, I’m have a little issue with both my blog & author permalinks.

At the moment I’m using the standard year/month/title for the permalink structure, I want to adapt this with the introduction of blog so blog/year/month/title.

My only issue when doing this is it knocks off my custom about prefix for author profiles which uses the following code

function change_author_permalinks() {
    global $wp_rewrite;
    $wp_rewrite->author_base = 'about';
    $wp_rewrite->flush_rules();}
add_action('init','change_author_permalinks');

This causes my author profiles to be accessible only via blog/about

Any thoughts on how I can retain just the about prefix for my author profiles whilst keeping blog in my structure for standard blog post.

Cheers