There is a test you can run to verify the machine OR the recording....
Play back the DVD until you see jumping....now pause the recording and take it back to the point 5 seconds BEFORE it starts jumping....then play it. Over and over if you have to....
You want to see if the jumping starts, and occurs on the DVD in the SAME EXACT SPOT....
If it does occur in the same exact spot, it's the DVD disc, and it's recording....
If it occurs ANYWHERE....then the DVD PLAYER has a problem.
That is the REAL KEY to isolating the problem to the DVD, OR the DVD PLAYER.....
Now obviously you should check several Different DVDs and ALSO note if the jumping occurs with a lot of BRIGHTNESS in it, like an outdoor scene ,or if it occurs in a Dark scene....
WHITE can cause jumping and it would be the PLAYER at fault, unless it's a real BAD recording....
But if it's the player, then ANY Bright or Dark scene will cause the jumping on ANY DVD you put in there.....
Once again, that's real Key to isolating the problem to the DVD or DVD player.....