If they've shipped 33.5 million and only sold 31.8 million it stands to reason they're holding back stock within the distribution chain. It's a bit strange to suggest those 1.7 million units are being withheld until they can make a profit because those units are made already, so they will be sold at a loss regardless. If those 1.7 million PS3s are out there then I have no idea why they aren't on shop shelves.
“The fundamental cause of the trouble is that in the modern world the stupid are cocksure while the intelligent are full of doubt.” - Bertrand Russell
"When the power of love overcomes the love of power, the world will know peace."
Jimi Hendrix