Razor burn is usually caused by using too much pressure. Right around the throat can be a tough spot, everyone is different, in time you'll find what works for you.
If you rolled your edge, you'll find youself using more pressure to cut hair, which could be why you're having irritation. If you think you dulled your blade, pay for the shipping, and I'll look at it and touch it up if it needs it. Or look around your area for a member and see if they will look at it for you.
I would suggest reading through Larry Andreassen's shaving manual, it will help explain the why's and why not's. Under NEWBIE HELP: Contents