Thumbnail Sharpening help

[whitefoxes]

Hi there. I just installed a fresh copy of Coppermine on my local server and it's all working fine except for the sharpening tool, no matter the settings I put in there, nothing happens to my thumbnails after I update them/upload new. It's not a cache problem as I have tried even deleting the thumbnails in the host folder and updating them again after that with Admin Tools. I have GD Version 2x, I have no choice of anything else. This worked fine on a previous install a few months ago on my local server. Lost it all so here I am redoing it all but for some reason it's not working the same this time. I do have the unsharpen mask ticked and set to 500% sharpen with nothing happening.

Any help appreciated.