Description:
------------
I am using the following code.
When our users upload files through this code... 
The is_uploaded_file returns false randomly but not always. 


if(isset($_REQUEST['action'])){
  echo "submitted";
  echo "<pre>";
  // print_r($_REQUEST);
  print_r($_FILES);
  echo "</pre>";
  $tempName = $_FILES["user_image"]["tmp_name"];
  if (is_uploaded_file($tempName)){
    echo "Yes Uploaded <br>";
  }else{
    echo "Not Uploaded   is_uploaded_file() failed <br>";
  }
}
?>
<form name="form_main" method="post" enctype="multipart/form-data" action="<?php echo $_SERVER['PHP_SELF'];?>">
<table width='100%'><tr><td valign='top'>
<table width='75%' align='center' cellpadding=5 cellspacing=1>
<tr class='user2'><td><b>Image : </b></td><td><input type="file" name="user_image" size="40"></td></tr>
<tr class='user2'><td>&nbsp;</td><td><INPUT TYPE="submit" name="action" value="submit"></td></tr>
</table>
</td></tr></table>
</form>

Please give me a solution or any alternatives for this.