[Plugin: Contact Form 7] CAPTCHA width fix

Really Simple CAPTCHA plugin that WPCF7 (v7.3.2.1) uses has a default char_length = 4 (no. of chars in CAPTCHA).

The default width settings for small, medium and large are in modules/captcha.php lines 459-481:

if ( $image_size = array_shift( $image_size_array ) ) {
		preg_match( '%^size:([smlSML])$%', $image_size, $is_matches );
		switch ( strtolower( $is_matches[1] ) ) {
			case 's':
				$op['img_size'] = array( 60, 20 );
				$op['base'] = array( 6, 15 );
				$op['font_size'] = 11;
				$op['font_char_width'] = 13;
				break;
			case 'l':
				$op['img_size'] = array( 84, 28 );
				$op['base'] = array( 6, 20 );
				$op['font_size'] = 17;
				$op['font_char_width'] = 19;
				break;
			case 'm':
			default:
				$op['img_size'] = array( 72, 24 );
				$op['base'] = array( 6, 18 );
				$op['font_size'] = 14;
				$op['font_char_width'] = 15;
		}
	}

The $op(‘img_size’][0] values can be doubled to accomodate upto 8 chars for char_length by editing the really-simple-captcha.php (v1.5) at line 36 to override the captcha default of 4:
$op['char_length'] = 6;

http://wordpress.org/extend/plugins/contact-form-7/