Seamless/Perfect diagonal stripe patterns

So I thought I had nailed it in 2 ways - first was by making a square and dividing it with equal rectangles, making it diagonal, and powerclipping it. Seemed like a perfect pattern, but turns out I was simply lucky with the calculations, and it wasn'd in fact PERFECT. I tried the same technique, and it proved it wasn't the way to make a perfect diagonal pattern. Second I tried blending stripes in a rectangle from one side to another. This method I reckon is alright for making designs for press or plotter, but NOT for perfect patterns, since I would have to calculate and cut the perfect square of the pattern myself.

So, I came here with a hope that there is a practical and efficient way to make PERFECT diagonal striped patterns in CorelDRAW. :)

Example: http://www.lizaphoenix.com/tiles/images/bluediagonalB.gif