The download of the Flash Files have always been about OK. As far as
I know, I don't think that Nokia restricts the download of Flash Update Files.

The simple logic for saying this is that if they were to restrict it then it would mean that they do not want people to update their IT Devices. Surely Nokia would not think about cutting off the hand that feeds them.

It is a possibility that the use of any other 3rd party down loader accelerator to download the 80+ Mb Flash files simply overwhelms the down loader.