I ran into an odd issue where PixelPipe wouldn't let me upload a video from my phone, but it would still upload pictures. I tried reauthorizing the facebook pipe on their website but it didn't help. I tried creating a new pipe and uploading through that and it still didn't work. What finally fixed the issue is reauthorizing the facebook pipe on the phone through the app.
Open Pixelpipe and goto the settings tab. Press the "Edit pipes" button.
This will take you to the list of pipes on your account. Press the combobox for facebook and press "change settings".
Scroll to the bottom of this page and press "Reauthorize this account".
It will ask for your facebook username and password. You might get dumped to a white screen with nothing on it. If this happens press the "back" device button and you should return to the Settings tab. Go back to the facebook pipe and check to see that the pipe has access to your account.