Well, it seems the problems are racking up now.

I'll been noticing when starting my 06 GT after it sits for several hours or overnight, that the brake pedal is rock hard. I've got a manual so the first thing I do before I startthe engineis press on the brake and then the clutch. Lately the brake pedal is rock hard with no movement when I first touch it. It hasn't always been this way. I had this same problem on my Probe GT and the brake booster had a leak in the diaphragm. Does this sound like the right diagnosis?

In the span of 2 weeks I've had three problems come up. It makes me worried when the warranty expires.

Mine does this too. I thought it was supposed to do that though because if you pump the brake a few times before starting it will harden up, then the second you turn it on it will release.

In this case I am not pumping the brake. It is hard the first time I touch it after parking. I'm making sure that I'm not discharging the vacuum when leaving the car. If I return within 1-3 hours, the pedal is still soft. After 4+ hours, it is hard.

Hmm...Never noticed this. To be honest, all I do when I start the car is put the gearbox in neutral, push in the clutch, and start the car. I'll try to remember to feel the brake before I start the car when I get done with work.