Thank you for the report! We're looking into a fix for this in the next version but until then you can try setting this in the settings file, under [General_Settings]:
CopyAsTempFile=false
If you need to locate the settings file you can find the paths
here.
The reason for the change was that we wanted to be able to paste selections of images into programs that only accepts image files, like Windows Explorer and some browser apps. But we'll reconsider the change as it seems to have slowed down other things a lot.