I was getting the same error and it was indeed gone after I forced the control to use Flash: uploader.UploadType = UploadType.Flash; My question now is this:What happens if the user doesn't have Flash installed? Does it fall back to Silverlight? Or does it simply fail? 

Hi Adam, Thank you for your answer. I inform you that gives the same error, I test it in the place that you sent me (http://ajaxuploader.com/Demo/Large-File-Upload.aspx). I sends the screenshot error!! The version of AjaxUploader is 2.0.0 Thank you, Juan

kriki:Hi Adam,   they are using McAffee Version 4.6.0.2292 with newest virus definition.   Does it happen to all browsers or one particular browser version?   How did you set UploadType Property?   Please disable the Flash, HTML5 and silverlight one by one and let me know how you can reproduce ...

Hi kumbsky, 1. The other settings are  Editor1.Setting[''InsertImage-CuteEditorFileStorageType''];Editor1.Setting[''ImageGalleryByBrowsing-CuteEditorFileStorageType''];Editor1.Setting[''InsertDocuemnt-CuteEditorFileStorageType''];Editor1.Setting[''InsertMedia-CuteEditorFileStorageType''];  2. What I mean is if your use the ...

DerekS: Hi Terry,   The folder is forgotten after just clicking the button again.   I'm using Vista SP1 and IE7   Testing it on the fulltest.aspx I found that :   The Auto and silverlight buttons didn't remember but the Flash and iframe buttons did.   On my site I tried using UploadType=Flash (as ...

Copy and paste this. Scroll to the very bottom of the page. Click on the button ''show modal'',and the tabs will appear. Click on the upload button now and you will see the bad block message. We can see that the green mask is right above at the top of the screen. If we scroll up and try again it works.  Let me know if you want ...

LiamPowell, I suggest you download the latest build and set up a temp folder then try again. http://ajaxuploader.com/document/index.htm#page=BeforeYouBegin.htm  

This issue has been fixed in the version 5.2.  Demo: http://cutesoft.net/example/general.aspx Download: http://cutesoft.net/Downloads/default.aspx Keep me posted  

This is how we are specifiying the control:   <CuteWebUI:Uploader ID=''fileUploader'' runat=''server'' InsertButtonID=''btnUpload'' CancelButtonID=''btnCancelUpload'' OnFileUploaded=''Uploader_FileUploaded'' OnFileValidating=''Uploader_FileValidating''> <ValidateOption AllowedFileExtensions=''doc, docx, pdf, ppt, pptx, pub, ...

For anyone interested in the answer It was enable parent paths in iis 6 must be turned on