Real3DFlipBook Plugin errow

Can anyone help be troubleshoot this error I am getting on the Real3DFlipBook plugin.
Here is the error
Warning: array_map() [function.array-map]: Argument #2 should be an array in /plugins/real3d-flipbook/includes/plugin-admin.php on line 135

Below are the lines where the code is throwing the error

$formatted = array_map("cast", $flipbooks[$current_id]["btnNext"]);
				$flipbooks[$current_id]["btnNext"] = $formatted;
				$formatted = array_map("cast", $flipbooks[$current_id]["btnPrev"]);
				$flipbooks[$current_id]["btnPrev"] = $formatted;
				$formatted = array_map("cast", $flipbooks[$current_id]["btnZoomIn"]);
				$flipbooks[$current_id]["btnZoomIn"] = $formatted;
				$formatted = array_map("cast", $flipbooks[$current_id]["btnZoomOut"]);
				$flipbooks[$current_id]["btnZoomOut"] = $formatted;
				$formatted = array_map("cast", $flipbooks[$current_id]["btnToc"]);
				$flipbooks[$current_id]["btnToc"] = $formatted;
				$formatted = array_map("cast", $flipbooks[$current_id]["btnThumbs"]);
				$flipbooks[$current_id]["btnThumbs"] = $formatted;
				$formatted = array_map("cast", $flipbooks[$current_id]["btnDownloadPages"]);
				$flipbooks[$current_id]["btnDownloadPages"] = $formatted;
				$formatted = array_map("cast", $flipbooks[$current_id]["btnDownloadPdf"]);
				$flipbooks[$current_id]["btnDownloadPdf"] = $formatted;
				$formatted = array_map("cast", $flipbooks[$current_id]["btnExpand"]);
				$flipbooks[$current_id]["btnExpand"] = $formatted;
				$formatted = array_map("cast", $flipbooks[$current_id]["btnExpandLightbox"]);
				$flipbooks[$current_id]["btnExpandLightbox"] = $formatted;
				$formatted = array_map("cast", $flipbooks[$current_id]["btnShare"]);
				$flipbooks[$current_id]["btnShare"] = $formatted;

				$formatted = array_map("cast", $flipbooks[$current_id]["deeplinking"]);