iPhone & iTunes playlists since iPhone update

I've just updated my software on my iPhone 3GS to 3.1.3 and now my playlists and albums on my iPhone play in random order. I've checked on my macbook pro and they play fine on the mac. The playlists appear ok on the iPhone but will not play in the order I created. I've read a few posts and they all refer to smart playlists but these are just normal playlists & as I said even CD's as downloaded won't play in order.... It's unbelievably frustrating!!!!..... Does anyone know a fix pleeeeeeeease?!..