I used to get these same clicks before I disabled 'legacy usb support' in the bios. I havent heard from them since. They were right at the start of a note as you say and would sound even if the attack was 40 or more.
Wolfram on the mailing list said...
"The "tick" is a little spike with around -48dB volume to sync MIDI
and audio to sample exact timing.
Usually you don't hear it because it's cleared out from the audio
stream. You can only hear it when the measurement went wrong, i.e. if
the tick came in too late or so.
And more importantly: the tick is only generated when there is
silence on the audio stream and the sequencer is stopped, it's not
generated as long as there are notes sounding or the sequencer is
playing back. So, it won't intefere with your music at all."
Mine was definately ticking when the sequencer was playing and when sound was being made, and it was not the click sound on fast envelopes that was part of the sound engine to make certain sounds (brass?) ala jp80xx or similar synths. Anyhow, as I say, doing that tweak in the bios fixed mine and fingers crossed it wont crop up again! Maybe its something to do with people having really old usb devices on the same bus as the TI or even having a saturated usb bus....I dunno
ten