Tire pressure question-too high psi?

[cjeezy]

Ok so this is probably a really stupid question, but I wanted to get some input. I recently put new Nitto tires on my Z. The sidewall says that the max pressure should not exceed 50 psi. Anyway, I set them all at 45 psi, however when my car was at the dealership they said that was "excessively high and dangerous" so they set them at 35 psi. So what is the right pressure? If 45 was too high then why doesn't the tire say 50?

Thanks in advance.