My regex's aren't what they could be, but after some experimentation with the code, the problem arises when you have a < before the </a>
also the problem would appear to be in your first regex (the while loop check).
looking at the reg exp , you've written it to exclude any data that has a < before the </a> the problem is with the ([^&lt;]+). you've specifically exluded any data with tags betweern the anchor tags.