I hope you don't mind me posting here, but i'm also having download issues.
(I made a topic about my problem 2 months ago, got one reply by peppy with only a possible cause, but no specifications on how to solve it and somewhen after it was put into the "resolved" category. It's still not resolved.)
I kind of don't want to open another topic for the exact same problem, so I hope I can post here.
Basically, since some time (several months) i've been unable to download maps from the official osu! Site or osu!direct.
My Internet connection is ~10mbps download speed and ~1mbps upload speed.
I usually download files at ~1,2mb/s so i'm pretty sure my internet is not the problem here.
Bloodcat downloads work fine, but i'm unable to download anything from the official sites/links/mirrors, whatever you wanna call them.
osu!direct just doesn't progress at all and sometime after i started the download cancels itself (Is at 0,00% or sometimes 0,1% at the time it cancels) and the official site shows me a download speed of ~0,1-1kb/s. This also cancels (or rather pauses) itself after some time (using Firefox 35.01).
I have tried using different browsers, was using Opera at the time when i made the first topic.
(Tried browsers: IE, Firefox, Opera, Chrome)
As stated before the only way I'm able to download maps is through bloodcat or other mirrors, those work fine.
Thanks, and again, sorry if I shouldn't post my own issues in another person's thread.
On topic: circlepit, you could try clearing cache/cookies, I guess.
I don't know much about how to resolve download issues since i am having one myself.