i have the same machine as you, and I too use Schmetz needles, but I tend to use Microtex needles for most things (apart from sewing with metallic thread).
I have found the Janome needles have a coloured coating on them (hence the red, blue purple colour coding) and, I know this sounds daft, but I have found that the coloured coating wears off, and the needle then drops out when sewing! The coating is thick enough to make a difference- or so it seems, and as I have had two Janome needles drop into the feed dogs and cause an almighty jam, I will not use them again!
I have used Schmetz needles in a variety of machines with never, ever any trouble. I do know that some Janome users prefer Organ needles, but I stick to what I know works!