Ugh

Yesterday, in a great fit of productivity, I started to baste my x-string quilt.  All went well until I got to the borders.  They will not lay flat.

   

Hello seam ripper.

I took the borders off while watching TV last night and when I got up this morning, I pressed everything really well.  I think the issue is that the quilt is on the bias and the strip is on the straight grain.  Something must have gotten stretched (or not) when the borders were added.  Now here's the debate:  try adding the border again or make some half x's to add to two sides.  I'm leaning towards retrying the border.  I have the backing and batting taped to my floor right in the middle of our living space.  If I make more x's, I will certainly have to pull that up.

Thoughts?  Ideas?