Why the industry jumped on photoshop as a web design and layout tool is beyond me. It's like trying to stir coffee with your thumb. I'm a descent photoshop user but have always used inDesign in web mode. Far quicker for chucking around layouts and options (as page). It also exports as rgb png's either full pages or selections with or without transparency (at any resolution). Which are perfect for then optimising in Photoshop (Pixelmator these days) or any other less costly image editor. I hand code my sites then in Coda, love it.