WP 3.1 rewrite problems

On the previous version of WordPress I created my own rewrite rule
i.e container.

I added the relevant rewrite entry i.e
add_filter(‘rewrite_rules_array’,’wp_insertMyRewriteRules’);

and entered the rule I wanted i.e:

$newrules[‘container/(.+?)/category/(.+?)/page/?([0-9]{1,})/?$’] = ‘index.php?container=$matches[1]&category_name=$matches[2]&paged=$matches[3]’;

** This is simplified version **

On WP3.05 and below this worked a treat. On WP3.1 The rewrite rules have introduce some new entries just below my entry which is redirecting my link back to a plain category link. i.e

mysite.com/container/books/category_name/library to
mysite.com/category_name/library

Anyone know how I can overcome this misbehavior?

Many thanks

PeterHuk