Are you referring to a ROLL type door that forms a roll above the header when open?
You cannot get them to seal at all, I have one, and it is the nature of the beast, they are corrugated and cannot be sealed on the edges, and the top has a large gap when closed. The gap goes away when you open as the roll gets larger.
A fix is to get a door taller than the opening, then the door is sliding past the header on its way up to the roll at a constant distance. The gap can be large, up to a couple of inches, and lets lots of air in and I also get birds this time of the year. They cannot get out, but they sure find their way in!
One fix is to use a rubber seal or brush seal like these.
http://www.sealeze.com/large.htm
http://www.bnd.com.au/content/?action=getfile&id=330
I have some L shaped metal trim left over from the construction, so I am making a hinged panel using the trim and a section of 3/4 conduit for strength and a pivot shaft. It will require opening manually first, before the door, but it will keep the flow of cold air out and the birds also.
Charles