Shuffle songs poor results

[Lozypants]

For a while now ive found that when i go into 'songs' and choose shuffle, its generating a queue with the same 3 or 4 artists from albums iv recently added.
Its very frustrating to say the least and forces me to listen to a Daily Mix play list instead, but the songlists there are also not updated often.
I want to listen to MY downloaded songs in random order!
Interestingly enough, iv found the shuffle option works perfectly if you play it offline.
I only discovered this because im a frequent flyer and found that the shuffle results are perfect when your phone is on flight safe mode.
It seems, for some reason, the algorithm used offline is different to the one used online (and produces better results!)
Obviously this isn't an ideal solution as pairing the device via wifi then becomes impossible and your phone itself becomes uncontactable.
Iv even tried generating the PROPER shuffle queue offline then turning flightsafe off again, but the que doesn't stay the same....why is this happening?!