Well, I am sure this is a re-run topic for thousands of other previous Spotify customers, but I am NOT going to keep paying for a service where I have to unistall my app a couple times a month and then reinstall it and then re-download all my content.... why would I do that? I will simply try one of the other providers in the marketplace.
Spotify - if you can't figure out how to solve this problem after NINE months, then you do not deserve your customer's money or support.
It is simply not acceptable for this issue to go this long unresolved, and I am fairly certain I should also file a significantly not as described complaint with my credit card provider for at least one month's service.
Anyway, done here.... I would possibly come back if you actually fix the 'can't login in offline mode' issue, but time will tell. Other service providers may have come through with a better product for me already, and it may well be too late...