PPSSPP as Windows Shell

[ShinDNA]

Hey guys, I'm new here and also new using the emulator.
I'm quite impressed by the quality of the emulator and I love the interface, so I tried forcing Windows 8 into accepting PPSSPP as it's shell.
I've done it before with Steam, XBMC and Windows Media Center and all of them work with no problem.
I forced PPSSPP into starting in full screen, and that all works fine, the problem is, when I start the dedicated user I created, PPSSPP crashed and tells me it can't find ui_atlas.zim in the assets folder, even though I've never touched it.
If I turn it off, turn the explorer on and then turn on PPSSPP again, it works fine.

Any reason why this happens? Any solution?
Thanks in advance guys!