To resolve the issue and show the image of all event categories, please replace the getCategoryImage function in jeventcal.php with the function(s) below.
Code probably needs clean-up.
	function getCategoryImage( ){
		$data = $this->getCategoryData();
		if (is_array($data)) {
			$count = count($data);
			$retVal = "";
			for ($iCount = 0; $iCount <$count; $iCount++) {
				$iData = $data[$iCount];
				$retVal .= $this->getOneCategoryImage($iData);
			}
			return $retVal;
		}
		else
		{
			return $this->getOneCategoryImage($data);
		}
		return "";
	}
	function getOneCategoryImage ($data) {
		if ($data){
			if (JVersion::isCompatible("1.6.0") ){
				$params = json_decode($data->params);
				if (isset($params->image)){ 
					return "<img src = '".JURI::root().$params->image."' class='catimage' />";
				}								
			}
			else {
				$image = $data->image;
				if (!empty ($image)){ 
					return "<img src = '".JURI::root().$image."' class='catimage' />";
				}												
			}			
		}
		return "";
	} Cheers and enjoy
