is the name of the page your form is on "DiscogDate.php"?
try changing the action of the form to be blank:
<form action="" method="post" enctype="multipart/form-data" name="uploadcsv">
If you are still having problems, add the following code at line to make sure a php error is not occurring:
also go to the bindings panel and expand the WA Uploaded files Global Status binding group and add the Debug info binding to the page, report back any php errors and the debug info after trying to upload another file.