This is normal with the yarn, it's not a defect. It helps if you knit them loosely or at a larger gauge. I knit a shawl with the country on 7mm needles and had very little problem with it splitting. I have some spa to make another and will use the same size. BTW I first made the shawl in a different pattern and ripped it out to reknit in another. Didn't have a problem with fraying. Maybe it was the larger needle...? You don't have to go up that large, but it can be knit very nicely on size 9 or 10s and that should alleviate the problems.
sue- knitting heretic