My Janome 6500 was terrible going over seam junctions. It veered off, jammed, balked, growled and broke needles. My Juki doesn't even give a hick-up over multiple layers and powers through everything. Some machines are just better at layers than others. Pin on each side of the intersection, stitch slowly and guide it carefully. Good luck with this ever so annoying problem.

I don't know if you can get a 1/4"walking foot for your machine, I bought one for my Janome and and it work great. It goes up and over bulky seam in a straight line, no more veering off.

when flying geese units are giving me a hard time i do them the way Holice described- i put needle down at the center point- stitch to the outer edge, clip, turn & go back to center to stitch the other half. this method has worked very well for me. sometimes i pin on each side of the center and slow way down...but the sewing from center out seems to really work the best.