I tried dual extrusion today and I have these oozing (or not oozing, you name it) in some places.
All the rest of the model is perfect except the spots I ruined accidentally
See images attached.
Sorry for the image quality.

IMG_1413.jpg
IMG_1415.jpg

Also, the printing seems to stop for a few seconds every time it finishes a layer just before advancing to 2nd extruder. Is this normal?