Can't order from some etailer sites, keeps logging me off, but not really...

[a6m]

Hello all, first post and really in need of some help.

First off I am running IE8 and use Norton for all my security stuff.

The problem:

All of a sudden, some etailer sites that I try to purchase things from will not proceed past the cart screen, when click on 'checkout' it just goes back to the cart. Now I had this problem with another site a few months ago and fixed it, albeit accidently and don't remember what I did. Have tried everything, I'm set to accept all cookies, have tried running IE without add-ons, nothing helps. The site is in my 'allowed' list so not sure what is happening.

Any ideas?

thnx