I've got the following problem:

When I start downloading a small file [like an mp3 or something] it just acts normal and the file will be downloaded in a few moments.

When I try to download a large file [like an 800 MB movie] nothing happens.
"More sources needed" or "unable to download" is shown in the statusbar, but there are more than 50 sources....

And sorry for my bad language i'm dutch but I don't use drugs!