[MongarEric]

This happened to me, I think after I opened the program TouchPro Tweak. I remember looking at a setting to disable the not-certified warning. It was already set to "disabled", so I didn't change anything. But before I had ever run this program, everything installed great.

I tried deleting the reg keys as suggested in piranah's post, but that just resulted in me getting the "not-certified" warning when I try to install cabs. When I try facemob's suggestion of setting the value of 00001005 to 40, it goes back to just saying the installation was unsuccessful when I try to install a cab file. I feel like I'm getting close.