>I am using the latest 2.6.7 kernel (tried also 2.6.5) but with hdsp I cannot s >elect anything lower than 1024x2 buffer settings in jackd without having massi >ve xruns.
Give up on 2.6 for now. If you can't give up on it, then at least run all (audio) apps with the environment variable LD_ASSUME_KERNEL set to 2.4.19. When the dust settles from the kernel and NPTL, 2.6 will be more viable. Right now, even though it works for some people, its not a generally viable platform for realtime audio. --p