A recent upgrade to the latest version of Phonegap seems to have introduced an intermittent upload error issue.

Randomly it will return “error code 3”. This is from what I understand a connection issue. In the code I am outputting the progress of the upload. The error randomly occurs at different stages of the upload.

I eventually found that there is a bug report at https://issues.apache.org/jira/browse/CB-2293

Two options seemed to help prevent the issue from occurring, disable chunked mode and set the connection to close in the header.

var options = new FileUploadOptions();
options.headers = {
	Connection: "close"
}
options.chunkedMode = false;

ft.upload(imgUrl, PATH, uploadSuccess, uploadFail, options);