What do you use for slicing images?

Some sites are designed so that illustration images merge with buttons with rollover capability ;

I am designing a lay out for a site in two steps : first the image “OFF” state and 2nd exactly the same image but with some collors changes for the “ON” state buttons ;

My main trouble will be slicing with precision and create the table so that there will be no staggering effect when rollover occurs ;

I´ve tried Ulead Smart Saver which proved not to be a friendly tool ;

So what do you recommend me for slicing ???

Cheers