Self winding mechanical watch problem

[Nepunet]

Okay, so I recently got this self winding mechanical watch from China.. it's the first watch I've had that hasn't been quartz.

The problem is - I can't get it to work. I initially wound it up and it started ticking away quite happily, but it then stopped altogether. I pulled out the crown and adjusted the time, and it began moving again for a moment - and then stopped again. I adjusted the time again, and it started again. This continued for a while, until the watch just stopped moving altogether. No amount of winding does anything about this, but shaking it from side to side for a while makes the mechanism inside move (as seen from the back) but the hands remain stationary. Sometimes the second hand "vibrates" forwards and backwards for a second or so.

Any ideas what I'm doing wrong or how I can get it moving again?