Custom Paging for Views does not work

I create custom views and print out pager in my views template as below:

if ($pager):
print_r($pager);
endif;

However, the pagination does not work. When I click on next or page number, nothing happened. Then I realize that it is due to url coding generated by Drupal. The link to another page is rendered as: [page-name]&[page-number], but when I replace & with & using firebug, the pagination works. How to tell Drupal to recognize special characters in urls? Or how to replace these special characters with ASCII characters.

Thanks