[tobico]

I think this is often a problem of dividing responsibilities.

In order to turn a design into correct CSS, the size and position of each element needs to be measured precisely. If the Photoshop-using designer can't or won't do this themselves, and send through clearly specified requirements, it falls to devs who probably aren't Photoshop experts, don't know what the designer was thinking, and might not even have Photoshop.

A nice side effect of having clear requirements is that everyone in the team can easily refer back to them to spot design bugs, not just the designer.