When I bought my C91 Upgrade (about 4 weeks ago) it did pretty much the same thing.
it would open random programs, change settings, get on the internet and do all sorts of annoying stuff, all without me touching anything.
I contacted the seller and he told me that the wire connecting the touchscreen inside the device was probably loose. He told me how to fix it, and it then worked perfectly.
You need to be fairly handy, and have a small Phillips head electronics or jewelers screwdriver.
1, Take off the back cover. Do this by undoing the two small screws on the end of the device with the input output ports. now with a thin flathead screwdriver or knife gently lever the white back cover away from the black device housing. you should get a small opening. Do this on the end with the input output ports. Try to leave the driver or knife in the opening to leave it open while you place the corner of a credit card in the opening. Now slide the credit card along edge between white and black covers pressing in at the same time. The cover should start to snap open. Do the same thing along one long side of device then the other. You should be able to now remove the white back cover being aware there are two speaker wires attaching the white cover to the other half of the device. This processes is a bit tricky the first time, but it can be done. Also be aware you might void your warranty if you open the device up.
2, locating and reconnecting loose screen wire. With the screen side face down and with the input output end on your right hand side. You should see a yellow flap next to where the speaker wires are connected to the device. Leaver the flap up and you will see a small white ribbon cable connected to a small white port with a black sleeve. if the sleeve is loose or not sitting flush with the white port, your in luck. Loosen sleeve, push in white cable with a pair tweezers or your fingers if you can. while holding the cable firmly in place slide the black sleeve flush against the white cable port and your done.
You can test the device while it is still apart to make sure it works properly. Now reassemble making sure the camera button is in place. This can fall out when you take the device apart.
Good luck.
I have taken some photo's, not sure how to attach yet. will try and attach them soon.
Hopefully somebody can help with my problem now. (my ZT pad wont boot up past the Android Screen) This is unrelated to the problem I have explained how to fix.
