I had this same problem a while back searching for some (apparently) exclusive Sam Rivers albums. Try this. Bring up any (one) album. Then click the "Keith Jarrett" link under that album title. This should go to a main page with a colour photo of Jarrett (or whatever artist you're searching) and all his albums will appear underneath.
But the albums are grouped - ECM albums, Solo Recordings, Recordings with Peacock & DeJohnette and so on.
The Aussie store looks like this...
To be honest I hardly ever download, but I'm glad Scott Dolan mentioned it was clunky, I thought it was just me too!