I tried to use sniper today,but
it will not let me sign in. My info is correct, I even changed my password. I can sign into eBay, but not sniper. Help

You have to enter your eBay user id and password exactly as you do when login on eBay.
Also, your password must be secure enough (you don't get a warning screen about your password being too weak when login on eBay).

If you believe your login is good, please let me know your eBay user id (no password please) so I could check.