ARGH!!!! Help with black and white "checkered flag" fabric please!!!

I'm attempting to make some simple curtains and valance for my son's bedroom.  I want the valance to be in black and white checkered flag fabric and the drapes to be in a bright red color (he's a big racing fan).  I've washed all the fabric and ironed it.  Here's the problem...I think the pattern on the fabric is crooked or something.  The pattern is 2 inch square blocks.  It looks straight along the selvages, but when I lined up the fabric to cut the other direction, it was crooked.  If I were to cut perfectly perpendicular to the selvage, I would start along the pattern line, but end up in the middle of a block.  Does this make any sense?  I've tried pulling the cattycorner ends to stretch the fabric both directions and it didn't help much.  Should I just cut along the pattern?  If I do that, will my valance end up hanging crooked?Hope all this makes sense...I'm a newbie and don't know all the terms yet  ;)Thanks!!!

Are the valances going to be tight across the top, or will there be a little gather/ ruffle type?  If it will have a little ruffle to it and across the top then you probably wouldn't notice if its a little crocked. 

I would use a mat and a ruler and line up the squares so that it looks straight.  Then use the ruler and a rotary cuter to cut the fabric.  That is my advice, but I'm new too so someone else might have a better suggestion. 

Good Luck!

There is going to be a little amount of gather.  The width will be close to one and a half times the width of the window.  I think it will hide ok at the top, but I'm not sure about the bottom.  I'll probably be the only one to notice if its a little crooked or the fabric pattern is a little off, right?  Ok, so my mechanical-engineer-anal-retentive husband will notice before me....

Can you rip the fabric with the grainline rather than cutting it to check how the pattern looks against that?  If it is crooked against a grainline rip, then yes, the pattern is printed on there crooked.  Marie Grace shows how this works on her blog (she's doing a tute for something else but the technique still applies).

http://www.mariegrace.typepad.com/

Scroll about halfway down to find the rip and square technique I am talking about.

If the pattern is in fact crooked, then you'll have to cut it just as luckydux describes.

hope that helps
trina