I agree with you, the border doesn't look right. I think it doesn't look like it belongs because there's no pieces inside the quilt that it matches and because the border's pattern also seems more busy than the other patterns in the quilt. I think it's lacking continuity because of these reasons even though the colors are right.
I really struggle with color and pattern choices in fabrics. My wife described some fabrics I was watching on Ebay as "interesting". I don't think she meant it in a good way.
Rodney