There is still an issue with users on Windows 7 systems, running Mozilla FireFox or Google Chrome.  We have the latest build:

AjaxUploader 3.0 20090708.  The upload works just fine on Internet Explorer.  We are also running the DLL in an SSL encrypted site.  Please advise.  We get the same error:

You are probably hitting the file upload limit of IIS7.By default in IIS 7 requestFiltering  has the MaxAllowedContentLength property enabled.It specifies, in bytes, the maximum length of the content in a request. The default is 30MB.