Page break dont work

Hi, i have a problem with page break tag, in my website i have a product section(i’ve published a page for that) in that page are 21 products, so i had to put page break tags, the structure is this: 7 produts and a page break, another 7 products and a page break and the last 7 products. The problem is this: there are 3 pages listed at the bottom, page 1 work well, but when i click the second appears the Post a comment form instead the second product page, this happens when i published that page, what can i do to correct this problem?????

Thanks