With trying to keep up with new versions of Zyn, Yoshimi & Rosegarden
my system is getting very fragile.

Originally based on 64studio V3 (beta) I've had to shoehorn bits in
from repositories as new as debian squeeze. It only now takes the
slightest mistake with an upgrade before the whole lot comes crashing
down around my ears :(

I've also made several attempts with ubuntu studio but found that
quite hopeless on every occasion.

After the most recent collapse I tried a different approach. I
installed a fresh debian squeeze then added rt kernels from
http://oselas.org/software/linux-rt/debian_en.html

I installed both the nnn.29 and nnn.31 versions so I could try them both
and see what differences there were. In fact they seem to behave about
the same.

They work, but performance is very poor. Jack seems to want to boot
things out very quickly. With the latest (nio) build of Zyn the sound
breaks up with the processors at around 45%, at about the same level
Yoshimi gets booted out by jack. Previously I could get up to the 60-70%
mark with these, and they never actually got booted - just sound
breakup.

The Rosegarden/Zyn/Jammin combo I used quite a bit in the past is quite
unstable. Rosegarden even seems to lose the timing!

I've done the usual settings in /etc/security/limits.conf but wonder if
there are any other performance settings I'm should to alter elsewhere.

As if this isn't enough, I can no longer get my MIDIsport working. It
identifies itself quite correctly with the script I run, but then comes
back with the message, 'can't open for input'.

Needless to say, this is extremely frustrating. I don't want to go
through the day-and-a-half procedure of rebuilding from the old 64studio
again - and risking adding just the bit that breaks it all again - but
I'm at a complete loss as to how to resolve this.