Please forgive me. I'm kind of a beginner when it comes to this stuff. So, I built a photo upload script using PHP/MySQL. Within the script photos are re-sized and given a temporary name while being uploaded.

I initially tested the script using several pictures (file size 220 KB | 960 x 720) everything worked just fine. Then I attempted to upload several pictures from my digital camera (file size 2.47 MB | 3000 x 4000) and all of a sudden I got this error:

Warning: getimagesize() [function.getimagesize]: Filename cannot be empty in /php_parsers/photo_system.php on line 94

Warning: Cannot modify header information - headers already sent by (output started at /php_parsers/photo_system.php:94) in /php_parsers/photo_system.php on line 96


I checked other posts to see if there is already a resolution posted in these forums but could never find a scenario where the file upload would work for some files but not others. Anyway, here is the code I'm working with. I've commented the offending line 94 and 96. Any help you could give would be greatly appreciated!

Code:
<?php 
if (isset($_FILES["photo"]["name"]) && isset($_POST["gallery"])){
	$sql = "SELECT COUNT(id) FROM photos WHERE user='$log_username'";
	$query = mysqli_query($db_conx, $sql);
	$row = mysqli_fetch_row($query);
	if($row[0] > 79){
		header("location: ../message.php?msg=The system allows only 80 pictures total");
        exit();	
	}
	$gallery = preg_replace('#[^a-z 0-9,]#i', '', $_POST["gallery"]);
	$fileName = $_FILES["photo"]["name"];
        $fileTmpLoc = $_FILES["photo"]["tmp_name"];
	$fileType = $_FILES["photo"]["type"];
	$fileSize = $_FILES["photo"]["size"];
	$fileErrorMsg = $_FILES["photo"]["error"];
	$kaboom = explode(".", $fileName);
	$fileExt = end($kaboom);
	$db_file_name = date("DMjGisY")."".rand(1000,9999).".".$fileExt; // WedFeb272120452013RAND.jpg
	list($width, $height) = getimagesize($fileTmpLoc); //OFFENDING LINE 94
	if($width < 10 || $height < 10){
		header("location: ../message.php?msg=ERROR: That image has no dimensions"); //OFFENDING LINE 96
        exit();	
	}
	if($fileSize > 4194304) {
		header("location: ../message.php?msg=ERROR: Your image file was larger than 4mb");
		exit();	
	} else if (!preg_match("/\.(gif|jpg|png)$/i", $fileName) ) {
		header("location: ../message.php?msg=ERROR: Your image file was not jpg, gif or png type");
		exit();
	} else if ($fileErrorMsg == 1) {
		header("location: ../message.php?msg=ERROR: An unknown error occurred");
		exit();
	}
	$moveResult = move_uploaded_file($fileTmpLoc, "../user/$log_username/$db_file_name");
	if ($moveResult != true) {
		header("location: ../message.php?msg=ERROR: File upload failed");
		exit();
	}
	include_once("../php_includes/image_resize.php");
	$wmax = 800;
	$hmax = 600;
	if($width > $wmax || $height > $hmax){
		$target_file = "../user/$log_username/$db_file_name";
	    $resized_file = "../user/$log_username/$db_file_name";
		img_resize($target_file, $resized_file, $wmax, $hmax, $fileExt);
	}
	$sql = "INSERT INTO photos(user, gallery, filename, uploaddate) VALUES ('$log_username','$gallery','$db_file_name',now())";
	$query = mysqli_query($db_conx, $sql);
	mysqli_close($db_conx);
	header("location: ../photos.php?u=$log_username");
	exit();
}
?><?php 
if (isset($_POST["delete"]) && $_POST["id"] != ""){
	$id = preg_replace('#[^0-9]#', '', $_POST["id"]);
	$query = mysqli_query($db_conx, "SELECT user, filename FROM photos WHERE id='$id' LIMIT 1");
	$row = mysqli_fetch_row($query);
    $user = $row[0];
	$filename = $row[1];
	if($user == $log_username){
		$picurl = "../user/$log_username/$filename"; 
	    if (file_exists($picurl)) {
			unlink($picurl);
			$sql = "DELETE FROM photos WHERE id='$id' LIMIT 1";
	        $query = mysqli_query($db_conx, $sql);
		}
	}
	mysqli_close($db_conx);
	echo "deleted_ok";
	exit();
}
?>
Please help! I've been trying to figure this out for a week now and to no avail!