ISSUE:

When i arrange (bring-to-front/send-to-back/etc ) some lines that are obscured by the jpg i inserted, or when i send the jpg to back, it results in flickery scrolls and zooms.

So far, the only remedy is to remove the pic and reinsert. Simply closing and reopening the drawing doesn't resolve the flicker/delayed zoom/pan. I can't remember whether or not restarting VC6P itself helps. But, i know that removing the pic, closing the file, reopening the file, and reinserting the pic works.

ADDITIONAL about my experience flowing from/toward this issue:

By the way, using User-Defined Plane is nice. I only open-mindedly used it when i wanted to make sure that lines i trace/draw from a pic draw on a level that is relevant to the elevation of the pic in use. I strongly recommend new users to become familiar with it. It can save you an enourmous amount of time once you see that it obviates any need of drawing parts-specific cutting surfaces (at least if the surfaces to result only need to be flat.)

Similarly, i recently experienced that infinite planes can be a very good friend, especially 3-point created cutting planes. If i'd actually TRIED to use it productively last year, it would have spared me countless hours wasted on localized/individualized surfaces creations for cutting or lopping off steel in girders). Now, i just create infinite planes and delete the planes when done -- i learned that forgetting a plane is associated or where it is associated can mess up my model. So, i zealously delete -- not just break links of -- infinite planes almost immediately after they've served their creation purpose. If i have to edit, then it just gives me more practice. )