Are you running several other applications at the same time you are trying to play Machinarium?
Because, if you are, you... are... not... go... ing... to... get... any... wh... e... r...e
This game is a memory HOG!
So whats up? Are you playing the game all by its' lonesome or are you also streaming/uploading/tweeting/fweeping/shmeeping/etcetra-ing all at the same time?