problem downloading from IMDB

[hhwh]

using latest version under win7 x64.
cookies enabled, in both firefox (version 8) and ds.

i can download some trailers from imdb, but not all of them.
try downloading the trailer for melancholia http://www.imdb.com/title/tt1527186/.
it recognizes the proper file but download fails.

i can download the same trailer without problems using the standard firefox downloader.

i have tried it with flashgot and with downloadhelper extensions. both extract the proper video file url but ds won't download.