"is your board affected by the uploading problem?"
Summary
Yes. Sometimes the upload serial upload fails and usually it works correctly.
Details
My Due works correctly in many sessions. I bought it at Newark in USA. When I start working on a Sketch the Due works perfectly. I edit then Sketch, plug in the serial cable, upload the instructions to Due, and it is good. I use the Due to test performance. I disconnect the serial cable. I run the Due successfully. I power down the Due. I plug in the serial cable and use the Serial Monitor to receive messages from Due. The messages are shown on my PC video screen as good text messages from Due. I power down. I need to disconnect my custom electronics from the Due using a DB25 connector to enable any uploads. If I keep the DB25 connected to Due from my experimental board, it never uploads, so I disconnect the DB25. I write a new sketch, I plug in the USB cable for upload. Failure ! "No device found on COM7"
I exit the IDE 1.52. I start IDE again. Failure. I disconnect the USB cable and start over to try to upload again. Failure. I power down my PC and boot up everything. It works now. Upload successful.
Sometimes Serial Monitor fails also. Then it works after re-booting computer. It seems intermittent. Re-booting is not alays needed, sometimes, just closing IDE and starting IDE makes serial monitor work.