I have a new 2005 rx8 here in Ireland and it has about 1100 miles on th clock.The problem im having is that a couple of times i have been driving the car cold soon after taking off when i need use the brakes the pedal is rock hard to the feel.There doesnt seem to be any travel in the pedal and braking is very poor.Now this is NOT abs cutting in ,i have had abs in my last 6 cars so i know what that feels like and im a seeing the problem even at extremely gently tipping of the brakes.Also abs is working correctly when it needs to during hard braking.

Any idea's

 

Sounds like occasional loss of vacuum to me......no assist.

Can't say I've seen this problem here on the forum before, I'd be making a dealer appointment to check it out. Don't mess about, brakes are serious business.