I occasionally have small blips or dots on my screen that will not allow me to zoom all to include only my drawing. I try to zoom in to see what it is but when I zoom or try to erase it either does not appear in a tight zoom or is not captured in an erase window.
I have turned of layers one by one, turned blipmode off, defpoints off, purged and regenerated - it's still there. I am changing the drawings to pdfs and with that mystery dot my pdfs are a disaster.
 
I have set pdsize, pdmode to 3, and ddptype to different values – no change
 
I am able to draw a line from this mystery blip as it seems to be recognized as a node though no other osnap will detect it.
Any thoughts?

tryturningoff all the layers you can with them showing.thenthe select commandselect objects: ALLif it selects themhit erace