This is almost certainly not a GPO or Kontact problem, but it's really driving me nuts and you folks might be able to tell me where to start or who might know how to help.
The problem: periodic static -- 'popping & clicking' (more like scratching, actually) at very precise 65 second intervals. This happens not only to the sound coming from GPO, but also on straight audio tracks recorded into the computer via the audio/MIDI interface.
Dell D600 Latitiude with 1.25 memory
M-Audio Fastack Pro combo audio/MIDI interface
I don't know for certain, but do you have a demo version of a VST or Direct X instrument/effect installed? Some VST/Direct X effects/instruments plugins might do this - eg if you have installed demo versions - the regular 'scratch' noise is a form of protection and in some cases only kicks in after a while (eg 30 days) so is a real devil to trace as it will suddenly start one day and not on the day you have added anything to your computer. Others introduce regular 'silence' as an alternative. If you have lost track of which ones you have installed which ones are demo, fully paid for, etc, then if you suspect this might be the cause, the only answer is to uninstall them one at a time, starting with any you know you haven't paid for yet, wait 65 seconds and see if it is the culprit.
Thanks for your help on the periodic noise problem. I had help setting up this new system, and the guy who configured it 'threw on' a couple of his VST's 'for free.' They're sounds I'll never use--vintage synth type things--so I uninstalled them as you suggested. Initially, this appears to have solved the problem; no noise when playing back GPO sequences that were noisy before. Still have the noise in already-recorded audio piano tracks, but these I fear are compromised permanently and can't easily be cleaned up (a shame, because my friend played beautifully that day.)
I'll withold final judgement on this glitch, though, until I try the system at my country place where I'm running my gear off of solar panels through an inverter. Inverters are infamous for creating noise in many sensitive electronic devices, and may be part of the problem. For the moment, though, I'm considering the problem solved. So once again, thanks for your help (hey, I think I just 'doubled in the bass!')
This problem continued even after the solutions attempted above. So I called M-Audio (I'm using their Fastrack Pro interface) and tech support there seems to have located the problem. Or so they say--am still waiting to test this out. It was an IRQ conflict--my USB ports were sharing the same IRQ as my video card. Solution A? Re-install XP and everything--oy! Solution B: get a USB PCMCIA card, since this slot uses its own IRQ. Will post again once I've tried this solution in a session with my VERY patient pianist friend.