Thanks for contacting us. Yes, we are fixing the issue with the thumbnail size! Sorry about that. We will try to push the update as soon as possible. Regarding the send/receive problem, you should be able to send and receive with no problems. We tested the app on an iPad 3rd gen with no problems. One thing you may want to do is to select the photos you want to transfer using the web interface instead of the selector inside of the app to avoid the problem with the thumbnails.
I hope this helps! Let us know if you continue having issues uploading or downloading from your device.