Down the slippery slope - bias knitting problems

Oh dear what can the matter be? Quite a lot it appears. The knitting has gone all lop sided!

I had my suspicions when I knitted a tension swatch that all might not be well with the yarn I had Navajo plyed on the spinning wheel. This looping/chaining technique converts a single strand into a three ply yarn. It's quite simple when you get going, but  I was aware some over twisting had occurred while I was getting the hang of it.

I knew over twisted yarn can cause the knitted fabric to slope off in one direction, but the slope on the tension swatch was barely perceptible so I pressed on with the main garment sleeve. Thirty six cms.(15") of slip stitch pattern later not only do I have a bias on the fabric but one side is a good 5cms(2") longer than  the other.

Time for a cup of cocoa and burning some midnight oil while wading through Montese Stanley's "The Hand Knitter's Handbook - still the best book I have for finding better techniques and problem solving.

Along with  the over twisted yarn, loose stitches at the beginning of a purl row could well be part of the problem.  Apart from tightening the first purl stitches another suggestion Montese gave is to work a double chain selvedge on the over long edge. But that might not be suitable on a sleeve seam.

I'm hoping taking the yarn from the opposite direction of twist might help things. Another possibility for sorting the bias caused by the yarn, given by Montese, could be to incorporate twisted or plaited stocking stitches going in the opposite direction.

You often come across knitting or purling into the back of a stitch when shaping but I have never really considered the possibilities created by the use of rows of such stitches for forming basic fabrics. I am now quite fascinated and am busy making sample swatches of twisted and plaited stocking stitch.

I still love the yarn, I'm determined to make it behave and give me a new cosy cardigan - based on one I had when I was eight. Any other suggestions?