diff --git a/README.md b/README.md
index f71a4470..208825f8 100644
--- a/README.md
+++ b/README.md
@@ -38,6 +38,8 @@ h5ai is provided under the terms of the [MIT License](http://github.com/lrsjng/h
 * fixes path problems on servers running on Windows in PHP version
 * fixes broken links in custom headers/footers while zipped download enabled
 * fixes problems with thumbnails for files with single or double quotes in filename
+* improves zipped download
+
 
 ### v0.17 - *2011-11-28*
 
diff --git a/src/_h5ai/css/inc/main.less b/src/_h5ai/css/inc/main.less
index b1df578f..55ed8cd1 100644
--- a/src/_h5ai/css/inc/main.less
+++ b/src/_h5ai/css/inc/main.less
@@ -94,6 +94,14 @@ body > nav {
 		display: none;
 		float: right;
 		border-left: 1px solid rgb(231,231,231);
+		.transition(all 0.2s ease-in-out);
+
+		&.zipping {
+
+		}
+		&.failed {
+			background-color: rgba(255,0,0,0.5);
+		}
 	}
 }
 
diff --git a/src/_h5ai/js/inc/ZippedDownload.js b/src/_h5ai/js/inc/ZippedDownload.js
index b2388ab0..b9afae6d 100644
--- a/src/_h5ai/js/inc/ZippedDownload.js
+++ b/src/_h5ai/js/inc/ZippedDownload.js
@@ -7,21 +7,22 @@
 			y = 0,
 			$document = $(document),
 			$selectionRect = $("#selection-rect"),
+			selectedHrefsStr = "",
 			updateDownloadBtn = function () {
 
 				var $selected = $("#extended a.selected"),
-					$downloadBtn = $("#download"),
-					query, href;
+					$downloadBtn = $("#download");
 
-				if ($selected.size() > 0) {
+				selectedHrefsStr = "";
+				if ($selected.length) {
 					$selected.each(function () {
-						href = $(this).attr("href");
-						query = query ? query + ":" + href : href;
+
+						var href = $(this).attr("href");
+						selectedHrefsStr = selectedHrefsStr ? selectedHrefsStr + ":" + href : href;
 					});
-					query = H5AI.core.api() + "?action=zip&hrefs=" + query;
-					$downloadBtn.show().find("a").attr("href", query);
+					$downloadBtn.show();
 				} else {
-					$downloadBtn.hide().find("a").attr("href", "#");
+					$downloadBtn.hide();
 				}
 			},
 			selectionUpdate = function (event) {
@@ -94,6 +95,39 @@
 				if (H5AI.core.settings.zippedDownload) {
 					$("<li id='download'><a href='#'><img alt='download' /><span class='l10n-download'>download</span></a></li>")
 						.find("img").attr("src", H5AI.core.image("download")).end()
+						.find("a").click(function () {
+
+							$('#download').addClass('zipping');
+							$('#download img').attr('src', H5AI.core.image("loading"));
+							$.ajax({
+								url: H5AI.core.api(),
+								data: {
+									action: 'zip',
+									hrefs: selectedHrefsStr
+								},
+								type: 'POST',
+								dataType: 'json',
+								success: function (response) {
+
+									$('#download img').attr('src', H5AI.core.image("download"));
+									$('#download').removeClass('zipping');
+									if (response.status === 'ok') {
+										console.log("download worked!", response);
+										window.location = H5AI.core.api() + '?action=getzip&id=' + response.id;
+									} else {
+										console.log("download failed!", response);
+										$('#download').addClass('failed');
+										setTimeout(function () {
+											$('#download').removeClass('failed');
+										}, 1000);
+									}
+								},
+								failed: function () {
+									$('#download img').attr('src', H5AI.core.image("download"));
+									$('#download').removeClass('zipping');
+								}
+							});
+						}).end()
 						.appendTo($("#navbar"));
 
 					$("body>nav,body>footer,#tree").on("mousedown", noSelection);
diff --git a/src/_h5ai/php/api.php b/src/_h5ai/php/api.php
index c3d12b30..72330882 100644
--- a/src/_h5ai/php/api.php
+++ b/src/_h5ai/php/api.php
@@ -118,12 +118,26 @@ else if ($action === "zip") {
 	$hrefs = explode(":", trim($hrefs));
 	$zipFile = $zipit->zip($hrefs);
 
-	if ($zipFile === false) {
-		fail(2, "something went wrong while building the zip");
+	if ($zipFile) {
+		$response = array('status' => 'ok', 'id' => basename($zipFile), 'size' => filesize($zipFile));
+	} else {
+		$response = array('status' => 'failed', 'msg' => 'none');
 	}
+	echo json_encode($response);
+}
+
+
+else if ($action === "getzip") {
+
+	list($id) = checkKeys(array("id"));
+	fail(1, "zipped file not found: " . $id, !preg_match("/^h5ai-zip-/", $id));
+
+	$zipFile = str_replace("\\", "/", sys_get_temp_dir()) . "/" . $id;
+	fail(2, "zipped file not found: " . $id, !file_exists($zipFile));
 
 	header("Content-Disposition: attachment; filename=\"h5ai-selection.zip\"");
-	header("Content-Type: application/force-download");
+	// header("Content-Type: application/force-download");
+	header("Content-Type: application/octet-stream");
 	header("Content-Length: " . filesize($zipFile));
 	header("Connection: close");
 	readfile($zipFile);
diff --git a/src/_h5ai/php/inc/ZipIt.php b/src/_h5ai/php/inc/ZipIt.php
index 5e2c9022..cb67a953 100644
--- a/src/_h5ai/php/inc/ZipIt.php
+++ b/src/_h5ai/php/inc/ZipIt.php
@@ -13,17 +13,18 @@ class ZipIt {
 
 	public function zip($hrefs) {
 
-		$zipFile = tempnam("/tmp", "h5ai-download");
+		$zipFile = tempnam(sys_get_temp_dir(), "h5ai-zip-");
 		$zip = new ZipArchive();
 
 		if (!$zip->open($zipFile, ZIPARCHIVE::CREATE)) {
-			return false;
+			return null;
 		}
 
+		$zip->addEmptyDir("/");
 		foreach ($hrefs as $href) {
 			$d = safe_dirname($href, true);
 			$n = basename($href);
-			if ($this->h5ai->getHttpCode($this->h5ai->getAbsHref($d)) === "h5ai" && !$this->h5ai->ignoreThisFile($n)) {
+			if ($this->h5ai->getHttpCode($d) === "h5ai" && !$this->h5ai->ignoreThisFile($n)) {
 				$localFile = $this->h5ai->getAbsPath($href);
 				$file = preg_replace("!^" . $this->h5ai->getRootAbsPath() . "!", "", $localFile);
 				if (is_dir($localFile)) {
@@ -35,7 +36,7 @@ class ZipIt {
 		}
 
 		$zip->close();
-		return $zipFile;
+		return filesize($zipFile) ? $zipFile : null;
 	}