Yep I'm aware of this.
It's a problem of processing windows message while scraping, which "kills" the application repaint in the background (I might be too technical ahah).
I've tried to find a workaround but didn't put so much time on it, because I really wanted to fix your scraping bug ^^
I'll give it another go next week (might just be a simple call to repaint or refresh at a certain time on the main window).
PS: scraping might seem long on some games but it has to calculate the CRC checksum, and then scrape every picture, which can take some time when there are a lot of pictures available for the game.
EDIT: Ok, that's fixed ahah (app going to background), it will be included in the next release