I don't get afterimages when going to the next page usually, mainly only from using the menu. It seems like it is excessive from what you are saying, binbinbook. I think you should contact Astak.
Robertb is an Astak rep and is on this forum, you could send him a pm here Robertb
under contact info, then send private message. Robert is very helpful and would definitely look into it for you! Or email firstname.lastname@example.org
or call 866-368-8788