Larry, sitting over here near the New Madrid and Mt Carmel faults I have 
notice that here too. I learned to use the Regional table and then NOT 
put too much faith on arrival times. I think I had a multiple comment 
thread several years ago in which this was discussed in detail. I even 
uploaded my Winquake file and Univ of Southern Indiana files through 
Vase as comparision. I even used satellite time. I was told these tables 
were averages, not written in stone, and variations are to be expected 
over shorter distances.

Larry Conklin wrote:
>  I recorded a couple of small events the other day, a 2.9 followed 
> shortly by a 2.7, at a distance of around 200 miles.  I noticed that 
> when I turn on the P and S phase marker lines in Winquake, they don't 
> line up with the P and S phase markers (ie. the veritical arrows).  
> The amount of discrepancy depends on which table I select, and isn't 
> all that great unless I really zoom in tight.
>
> So, two questions.  Why the difference?  And which should I use to 
> estimate the distance to the event, the arrows or the phase lines?  
> (Not that it really makes much difference, since I usually have a lot 
> of uncertainty where the phase onsets are anyway.)
>
> Larry Conklin
> Liverpool, NY
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