AndrewC: I think it's more of a latency problem than anything else; satellite has extremely high latency which could cause auth errors for the downloader, which might be why it doesn't identify and resume downloads.
Firek: 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.
"Large" downloads (like UT2K4, Unreal II, Darkstar One) seemed to pull down smoothly when the Downloader was an Adobe AIR app, but that might have little to do with it. The CHUNK# files are only 10MB large, so I'm not sure if caching is an issue, but like I said before, this isn't exactly a cable-comparable connection.
I tried removing the game from the list, without actually deleting the files already downloaded, and haven't noticed any immediate improvement in connection or download speed. I'm loathe to download what I've already got (4636/8597MB). Is there a way to generate a trace report or something to diagnose possibilities before resorting to starting from scratch?