Small spool reels are prone to do this. Watch for a loose loop on the spool each time you cast. If you see any be sure and pull line off until you pull out the loop that has slipped off the spool. These almost always cause a major tangle.
To me 8# mono seems heavy for a light jig and especially on a small spool reel. You want the line to be limp as possible so it lays flat on the spool.
Just my 2cents worth.