I experienced that when the rubber spacer had the thick side up towards the rear of the phone, the display data cable would plug in but had enough pressure from the rubber bumper pushing up that it would eventually become partially unplugged. This may not be immediately apparent while putting the phone back together because of still being partially plugged in. This was not an issue when the thin side was installed facing up towards the back of the phone.
Make sure to align the hole on the vibrator to the hole on the frame for the screw that will attach the logic board.
I found removing the three screws on one side during reassembly made it easier to keep the washers on the opposite side in the correct position when installing the display. When the display is in place, reinstall the three screws and then snug down all six. Then back all off about a quarter to a half turn to assist in aligning the holes for the four corner screws. Only after all ten screws are in place should the screws be tightened. Be sure to gently squeeze the display down to the outer frame at each screw while tightening to eliminate any gaps between the two.
These Wi-Fi grounding fingers should be distinguished in the image that accompanies the instructions to show their location to ensure their identification to be cleaned and to be in the proper position upon reassembly. If I guess correctly, there is one by the screw on the left, two below the thumbnail in the image and a fourth that is blocked from view in the image by the logic board.
This was a remark made in the products section for the rear glass panel on the Verizon CDMA, "The instructions don't tell you to make sure that you remove the plastic lens from the front facing camera." It is referring to the protective plastic film on the new rear panel that protects the new lens. This should definitely be included in the instructions for replacement of the back panel.