diff --git a/lib/FileAPI.XHR.js b/lib/FileAPI.XHR.js
index 88f3bcbf..bb84a9fb 100644
--- a/lib/FileAPI.XHR.js
+++ b/lib/FileAPI.XHR.js
@@ -158,7 +158,7 @@
 				if ( options._chunked ) {
 					// chunked upload
 					if( xhr.upload ){
-						xhr.upload.addEventListener('progress', function (/**Event*/evt){
+						xhr.upload.addEventListener('progress', api.throttle(function (/**Event*/evt){
 							if (!data.retry) {
 							    // show progress only for correct chunk uploads
 								options.progress({
@@ -168,7 +168,7 @@
 									, totalSize:	data.size
 								}, _this, options);
 							}
-						}, false);
+						}, 100), false);
 					}
 
 					xhr.onreadystatechange = function (){
@@ -204,6 +204,9 @@
 										data.end = lkb;
 									} else {
 										data.end = data.start - 1;
+                                        if (416 == xhr.status) {
+                                            data.end = data.end - options.chunkSize;
+                                        }
 									}
 
 									setTimeout(function () {
@@ -237,6 +240,9 @@
 								}
 							}
 							xhr = null;
+                            if (slice) {
+                                slice = null;
+                            }
 						}
 					};
 
@@ -246,13 +252,20 @@
 					var slice;
 					(slice = 'slice') in data.file || (slice = 'mozSlice') in data.file || (slice = 'webkitSlice') in data.file;
 
-					xhr.setRequestHeader("Content-Range", "bytes " + data.start + "-" + data.end + "/" + data.size);
-					xhr.setRequestHeader("Content-Disposition", 'attachment; filename=' + encodeURIComponent(data.name));
-					xhr.setRequestHeader("Content-Type", data.type || "application/octet-stream");
-                    
-					slice = data.file[slice](data.start, data.end + 1);
-                 
-					xhr.send(slice);
+                    slice = data.file[slice](data.start, data.end + 1);
+
+                    if (data.size && !slice.size) {
+                        setTimeout(function () {
+                            _this.end(-1);
+                        })
+                    } else {
+                        xhr.setRequestHeader("Content-Range", "bytes " + data.start + "-" + data.end + "/" + data.size);
+                        xhr.setRequestHeader("Content-Disposition", 'attachment; filename=' + encodeURIComponent(data.name));
+                        xhr.setRequestHeader("Content-Type", data.type || "application/octet-stream");
+
+                        xhr.send(slice);
+                    }
+
 					slice = null;
 				} else {
 					// single piece upload