Unable to update

Hi there - I'm currently at version 1.5.1. I've downloaded 1.5.2 from Kemper's web site and placed the kaos.bin on my USB stick just like I've done with past updates, but for some reason - unlike previous times - my KPA doesn't recognize that there's a new version on the USB and it won't update. Any ideas?

Thanks! I had sort of tried that previously, but with overwriting the file on the USB stick with a file I had downloaded again from the web site (didn't work). But completely deleting the file from the USB stick and placing a new file on there again caused it to work... nice...