I'm consistently having a problem with slipped stitches with the Provence.
This problem is specifically confined to purl stitches.
To combat it, I do a thorough check ever couple of rows. If I see that long bar of yarn, indicating that there's a missed stitch behind it, I work over to that stitch, I grab my crochet hook, undo the column, and then reloop, picking up the missed stitch.
It's more of an annoyance than anything else, and probably due to where I'm doing most of the knitting (the subway, of course). When I'm on the train I tend to look anywhere else BUT my knitting (I can do this with stockinette). Purl stitches are a bit harder for me to knit by feel. Because this yarn is so slippery smooth, it's prone to popping off of the needle before I've looped it through the stitch.
Still, this yarn feels so wonderfully smooth and soft that it's worth risking a few (easily fixed) slipped stitches. And, I'm almost at the shoulder shaping, so it's not impeding my progress one bit.