Image Cannot Be Blank Problem

Hi,

I am trying to upload multiple images in a form using Yii. But when submitting the form it is showing 'image cannot be blank' to all the file inputs. When debugging I can see the file data in the $_FILES array but the post data shows empty. Below are the code snippets
My Controller

	for($i=1; $i<=$_POST['totalCount']; $i++)
			{
				$model=new ActivityBanners;
				$model->attributes=$_POST['ActivityBanners'];
				$model->iUId=Yii::app()->session['user_id'];
				$model->dtCreatedOn=date('Y-m-d H:i:s');
				$model->iStatus=1;
				$model->vcType=$_POST['ActivityBanners']['vcType'][$i];
				$vcTryImgInstance=CUploadedFile::getInstance($model,'vcImage['.$i.']');
				$try_file_name=$_POST['ActivityBanners']['vcType'][$i].'_'.rand().'_'.CustomHelper::fileNameGen($vcTryImgInstance);
				if($vcTryImgInstance!='')
				$model->vcImage=$try_file_name;
				if($model->validate())
				{
				if($model->save(false))
				{
					$res++;
				if($vcTryImgInstance!='')
				{
					$vcTryImgInstance->saveAs(Yii::app()->params['bannerUploadDir'].$try_file_name);
					$file= Yii::app()->params['bannerUploadDir'].$try_file_name;
					$img = Yii::app()->simpleImage->load($file);
					$img->resizeToWidth(Yii::app()->params['thumbSmallSize']);
					$img->save(Yii::app()->params['uploadBannerThumbDir'].$try_file_name);
				}
				}
				}
			
				
			}

Model Code:

public function rules()
	{
		// NOTE: you should only define rules for those attributes that
		// will receive user inputs.
		return array(
			array('iLangId, vcImage', 'required'),
			array('iLangId, iStatus, iUId', 'numerical', 'integerOnly'=>true),
			array('vcImage', 'length', 'max'=>512),
			array('vcType', 'length', 'max'=>100),
			array('dtCreatedOn, dtLastModified', 'safe'),
			array('vcImage', 'file', 'types'=>'jpg, gif, png,', 'maxSize' => 1024 * 1024 * 10,'tooLarge' => 'The file was larger than 10MB. Please upload a smaller file.',    'on' => 'insert'),
			// The following rule is used by search().
			// Please remove those attributes that should not be searched.
			array('iBannerId, iLangId, vcImage, vcType, iStatus, dtCreatedOn, dtLastModified, iUId', 'safe', 'on'=>'search'),
		);
	}

View Code

	foreach($activityBannerTypes as $values ) { 
		$i++;
		?>
	<div class="row">
		<?php echo $form->hiddenField($model,'vcType['.$i.']',array('value'=>$values)); ?>
		<?php echo$form->labelEx($model, $values.' '.'Image'); ?>
		<?php echo $form->fileField($model,'vcImage['.$i.']'); ?>
		<?php echo $form->error($model,'vcImage'); ?>
	</div>
	<?php } 

Thanks in Advance!!