This usually happens when you attemp to access a site that uses SSL encryption e.g pay sites, merchant sites etc. Its a security feature that protects you the user from accessing fake or dubios site setup by 419ers. Solution: Install firefox 3. i promise you, u wont regret it.
Whatever you access any e-Commerce or Shopping Cart online where it pop up security alert, it means their site has expired their SSL certificate.
You are very much risk trying to order from them that is expired SSL certificate. PLEASE DO NOT TRUST THEM!
Be sure on your IE, enable POP-UP BLOCKER that way you won't get annoying popups sites.
Be sure Nairaland.com on popups okay---allow it pop ups for spell check, recent replies, who's online, etc. as well as your favorite bookmark (all sites you use all the time) must be POPUPS OKAY button.
While other sites you never use or never see them before---disenabled POPUPS buttom turn "BLOCKED"
Otherwise switch to better browser, FIREFOX 3 as @samir101ng has said it all.
Hey u guys re not helpinq matter, how can i take security alert from my IE? u are recommendinq another browser 4 me. Damn! i like usinq IE 6 thats what i gat.