How can I fix my Singer Ultralock serger?

The thread that goes through the lower looper broke on my serger... I opened it up and re-threaded everything... and now all of the thread keeps getting all bunged up under the plate... I've tried re-threading numerous times, just in case I'd gotten it wrong, and still get the same result... So I've been on-line looking for a video or some type of instruction on how the inside of the serger is supposed to work and I've found nothing...

I've re-threaded and moved the wheel manually to see what was happening, and it looks like the threads are getting caught on the lower looper... When the needles go down, are they supposed to be in front or behind the lower looper? Any thoughts? Thanks!