Why can't I copy a selected area between pages anymore?

Do you want to copy from area by x1,y1,x2 and y2 in GPAGE p1 to area by x3,y3,x4 and y4 in GPAGE p2?

Sorry for being vague. In SB's GRP editor, I was once able to highlight an area with copy button, switch pages ( say from GRP4 to GRP0 ), and paste the selected area on a different page. The function used to leave an afterimage if you ended the copy function prematurely, as well. ( I was going to use this to help with sprite development ) But now when I attempt to copy something over to >>>

a different page, it unloads the image I was preparing to copy. I'm assuming either it was a glitch that they patched out, or I somehow screwed with the settings.

>Preparing to copy to a different page<

Gone.