I refreshed The Witcher across our file hosting provider's CDN a few hours ago. Please try restarting the Downloader, or remove The Witcher from its list and add it again. If that doesn't help, send me a PM and I'll ask you to send me the Downloader's log files to a specific e-mail address. These might help clear this up a bit.

Are you experiencing such problems with every large game, or just The Witcher and one or a few specific additional titles?

Oh, I completely missed the part about the satellite connection. That might complicate things, but we'll follow up with predcon via PM/e-mail.
Satellite connections like to have a lot of files cached to speed things up, so I've sometimes experienced problems when a user would keep redownloading the same, corrupt file that was cached on his ISP's end.
In such cases our file hosting provider needs to intervene, and that takes time and some additional data from the user.