Problem with appliques

I need you rhelp with sewing on appliques. I make my own appliques from the plain cotton fabric and use an iron on adhesive. After that I use special satin stitch on my sewing machine ot go around it - it creates a nice frame and secures the applique. I did it on a couple of outfits (I make doll's outfits), but the last one gave me a big fit. Glue from the adhesive keeps to stick on the machine needle and machine skips stitches, etc. I can not figure out what the problem is? I used the same iron on adhesive as before. What's the secret? Or may be I should not use iron on adhesive at all? In this case, do you just pin the appliques to the fabric? Thank you!!!