I'm trying to implement a file upload script, and the process seems pretty straightforward:

HTML Code:
 <form action="../main_scripts/process_insert_update_file.php" method="post" enctype="multipart/form-data"  >
    <label for="filelabel">File to upload (2 MB max):  <input name="uploadedfile" type="file" /></label>
   <input type="hidden" name="MAX_FILE_SIZE" value="2097152"/> <input type="hidden" name="action" value="upload"/>
      <input type="submit" value="Submit" />
(Of course I'll be doing plenty of validation after submission)

As a start, I'm just hitting submit, and then printing the values of $_FILES in my process script. What I'm finding is that both locally or on my production server, if I do a bunch of these submits in a row (in other words, submit -->look at my $_FILES array-->do this again with another file), that rather quickly, I'll need to double submit or php gets stuck. Might there be an explanation for this in terms of how php allocates memory? And if so, is there anyway around this?

Thank you for your help,