Oddball question about data synchronization in ResScan

Ok,

This is a weird question that probably only the nerds among us would care about. But it's been bugging me (as a nerdy mathematician) for about a week.

When I look at my detailed data in ResScan, the data on the graphs doesn't always line up. The problem is tied to the night the data is recorded: On some nights the events, flow data, leak data, etc. are all nicely lined up and the events pop up right where you'd expect them to----right at the end of the event. On other nights, there appears to be up to a three minute lag on the events, leak, pressure, and flow limitation data relative to the flow data. In other words, I can clearly see an apnea in the flow data ending at say 3:40:50, but the event peg doesn't show up until 3:43:50 and the flow data at that time is clearly rather normal breathing. When this happens, the flow data graph starts before any of the other data graphs start, and the gap between the start of the flow data and the other data graphs is equal to the lag between the end of the obvious events and the appearance of the event peg in the "events" graph.

Any ideas on what might be happening? Is it a flaw in my S9 AutoSet? Or is it clumsiness on my part in some part of how I put on my mask and turn the machine on?

Does this kind of quirk show up in anybody else's graphs?

There were several threads about this. If you do a search "data + skew + S9" you should find them. I don't think it was ever resolved, except that if you format your data card, then it will go away...for awhile, anyway.

Here's a recent update by DreamDiver, about skew:

viewtopic/t50970/viewtopic.php?f=1&t=50 ... ead#unread

Thanks for the useful links Katie. They have been illuminating to me. And it's good to know I'm not the only one who has been dealing with this problem.