On the older code if you didn't complete the Optimus or megatron MB in one go it would make you relock and start over in order to progress. Now there is an option to save progress. That is the roadblock people are referring too.
I actually still own mine and bought nib so I've gone through all of the code updates. I still enjoy mine when I play. Not the best player, and don't play often but still enjoy it. Kids like it too.