What was the solution they gave you? I have exactly the same problem, but strangely it has only arisen since I downloaded the new version of the Spotify app last week after the security alert. I have the same build number as you detailed (18.104.22.168). I have tried deleting caches, reinstalling apps and all that jazz to no avail. Start trying to download with 9.66Gb used on a 16Gb phone but only 3.55Gb used on a 32Gb SD, and still it goes to phone. Then, when the phone is full it won't let me download any more. Aargh! So annoying, because it was all working perfectly until they updated software last week.