Problem with Download Accelerators or what???

Since one month, I have been downloading a lot from dailymotion.com and youtube.com, using DownloadHelper. Well, DownloadHelper is an add-on in Firefox, which lets you download the streaming videos sort like the grabber. I used to copy the link and download it using DAP. Now, it doesn't accelerates any file at all. DAP asks me for authentication, my usual username and password for those sites doesn't seems to work. The same happened with youtube.com two weeks before dailymotion.com. I am not able to accelerate any downloads from this sites. I even changed my Download Accelerator to IDM, but still doesn't work.

How can I solve this problem??

PLEASE HELP ME.

THANKS IN ADVANCE.

Problem with Download Accelerators or what???myspace names

INTERNET connection problem . your connection has been corrupted.