Issue with <nextpage> – cross linsk to different stories

Hi,

I am using wp v2.2.2 for my hostorials.com
I also use <–nextpage–> tag to break long articles into multiple pages.

however when i use that, the multiple pages of the actual story gets cross linked to a completely different story.
Example: https://www.hostorials.com/2007/09/30/an-e-commerce-web-hosting-account-makes-accepting-credit-cards-easy/

Thank youf ro any help in fixing this.