Playstation 3

[Sally]

I have a new 80GB playstation 3 ( just done system update to v 2.52) I bought Ratchett and clank to play, put this in the machine and it says I need 419mb of free space on the hard drive to upload data relating to the game, i don't understand this as there is nothing on the hard drive only my partners boxing game. I've gone into system setting and it says there is 74gb of free space on the hard drive. Does anyone know why the game is asking of this if there is enough free space on the hard drive and could you please advise what I should do. Ta in advance