How are you logging in to the Forums?

Once you convert your game over to Steam, your characters should be on your STEAM account. When logging in, you want to not put in your old information in the login box but instead click on the green Login Via Steam button next to the Facebook button. This should allow you to pull up the information (and knights) associated with the Steam Account (steam:[your unique id]) instead of your old SK account.

Also, I'm not sure but the image displayed on the forums is not your actual knight image. You click on Forum Preferences next to the search box and then click edit to choose one of the images that is provided.

I hope this helps,

-Wolf