File Upload Broke When Moving Windows To Linux

I love yii and deeply appreciate the help this forum has provided!

Admittedly my best programming days are behind me, but I have an issue that's vexing me. I had this prototype running on my Windows 7 laptop (yii/php/apache/postgres), and when I went to move it to a linux server, my file uploads broke.

At first I thought it was the sessions, but I resolved that.
Then I thought it was permissions (the copied php files didn't have the execute bit set), but that seems to be okay now.

Been fighting it for many hours now, and I can't figure out what the issue is.
I have this in my "Files" controller for uploading & encrypting files:

public function actionCreate()
{
	$model=new Files;
	$securityManager =  new CSecurityManager;
	$securityManager->setEncryptionKey(Yii::app()->params['fileEncryptKey']);
	if(isset($_POST['Files']))
	{
		$model->attributes=$_POST['Files'];
		$fdate=$_POST['filedate'];
		$model->filedate=$fdate; 
           $model->url=CUploadedFile::getInstance($model,'url');
		// The following encrypts the file.  
		$tmpfile = CUploadedFile::getInstance($model,'url');
		$tmpfile_contents = file_get_contents( $tmpfile->tempName );
		$encfile_contents = $securityManager->encrypt(base64_encode$tmpfile_contents));
		file_put_contents( $tmpfile->tempName, $encfile_contents );
		$model->filename = $model->url;
		//$ffilename=$model->filename;
		$pid=$model->patient_id;
		// Create the directory if it doesn't exist
		if (is_dir(Yii::app()->basePath.'/datafiles/'.$pid)) {
			/* */
		} else {
			mkdir(Yii::app()->basePath.'/datafiles/'.$pid) ;
		}
		//var_dump($_FILES);die;
		if($model->save()) {
			$model->url->saveAs(Yii::app()->basePath.'/datafiles/'.$pid.'/'.$model->url);
			//$model->url = $model->url;
			$this->redirect(array('view','id'=>$model->id));
		} else {
			print_r($model->getErrors());
			throw new CHttpException(403,'Unable to save this file!');		
		}
	}

I originally had the "saveAs" before the "if($model->save)" and that yielded an encrypted file (in the final location) with a file name of "Object id #49" on linux, instead of "familypicutre.jpg" on Windows.

The behavior I am seeing is:

PHP error
Object of class CUploadedFile to string conversion

when it goes to do the validation during the save operation.

I also inserted a "var_dump($_FILES);die;" before the "save" on both Windows and linux, and they showed the exact same thing (other than the path diffs b/w the os's).

It's confusing, because the error looks like it's at the yii level, so I don't understand what the environment has to do with it. I think the *real* issue is that I don't really understand how the $model->url can act as a filename as well as a CUploadedFile object, but I based this off of an example, and I got it to work in Windows...

Any ideas??? Thx!