Corsair 450D - Front Panel Won't Latch

Hi all. I've run into an issue with my new case. As the title indicates, the front panel/grille will no longer stay shut. It was fine a few days ago but tonight, after installing the new I/O panel Corsair sent, it simply will not latch shut. It doesn't appear that anything was damaged or disturbed during the I/O panel replacement, so I'm at a complete loss.



Has anyone else experienced this problem or have any suggestions? Thanks for the help.