Copied lines acting wired / like referenced to the original one

Hey all, since a few weeks copied objects seem to be referenced somehow to eachother. For Example… when I copy a line from one point to another and keep on working with the copied line, it does the same things with the original one… its just a simple line. No block or anything special.
I’ve been using rhino now for several years. But never had such thing before. Updating Rhino didnt help.
any Ideas?
Thanks a lot! Phil

Although I never use it, I understand these kind of things happen when you have History set to On, could that be it?

Max.

awesome Maxz! That helped straight away! Thanks a lot! it was the ticked box “Update” which caused the problem.
Thanks again! bye, Philipp