[LAU] MIDI latency in Ubuntu 8.04

[David Baird]

When I use the kernels from Ubuntu 8.04, my MIDI latency becomes
horrible.  I have an external keyboard that connects to the computer
and then proceeds to loop-back out to external synthesizers.  By
horrible, I mean that there is quite clearly a delay from when I hit a
key on my keyboard to when sound comes out the synthesizer.  If
someone knows a tool I could use to measure the latency, I'd be glad
too.  Otherwise, I'd just guess it is somewhere around 100
milliseconds.

When I switch back to my prior kernel from Ubuntu 7.10, the latency
becomes great (but the X server and other things stop working, thanks
to the magic of Ubuntu).  Here are the kernels I've tried out with
Ubuntu 8.10:

2.6.24-18-generic

    Bad latency

2.6.24-18-rt

    Bad latency

2.6.22-14-generic

    (This is the kernel from Ubuntu 7.10)
    Excellent latency

Has anyone else had this problem?  Do you know if it is
kernel-related, library-related, or Ubuntu-related?  It almost seems
kernel-related, but why?

-David