R520 Jump from zip file to last folder

[gigapackiii]

R 520, Win7 64 Ultimate.

When I click into a .zip file and FC opens it automatically and shows the content.
But after about 5 seconds the window jumps to display the content of the last folder of the folder the zip file is in. It happens in about 90% of all zip files I have. I couldn't figure out a difference between the zip file where it does not happen.