Is Switching Jobs Too Often a Bad Thing?

Career Hot Potato asks: "I've been out of school for little more than a year and I have only good things to say about the job market. So far, there doesn't seem to be any lack of demand for a good .NET developer. I've got to admit, though, I feel a little disloyal at this point. Several great job offers have come my way and I've taken them. My resume is starting to make me look a bit restless and it worries me. Until now I've just chalked it up to 'I'm just settling in,' but now another opportunity has been dropped into my lap. Would I be digging my own grave by taking this job? It'd be my fourth job in 16 months but each offered a promotion and a 30% to 40% raise. I know better than to put a price on job satisfaction but I'm pretty certain I'd be happy there. Is being branded as a 'hot potato' enough to keep you from switching? What's your price on this stigma?"