I wonder, because I stumbled on such problem:

• I've created visitCount>=2 segment
• such segment works OK (meaning: it filters visits at least in Visitor Log as expected)
• problems start when I would like to view Visitor Profile Popup

On Visitor Profile Popup same segment is applied (https://github.com/piwik/piwik/blob/master/plugins/Live/API.php#L204), so when app looks for previous visits to be counted and listed below the current one, I get one less visit then I should (this is for for visitCount>=2 segment, for for visitCount>=3 there probably would be 2 missing, for for visitCount>=4 there would be 3 missing, etc... haven't check that behavior but it seems as a logical consequence).

This is misguiding, since most of such visits have visitCount=2, when I open respective visitor's profile, it looks like there are no additional visits.

At this I wonder whether data on Visitor's Profile Popup should be segmented at all. Since it just should show logs for specified visitor ID (https://github.com/piwik/piwik/blob/master/plugins/Live/API.php#L218) anything else shouldn't be filtered out. Ie. when I put segment for visits with more actions then 5, I expect Visitor Log to present such visits, but when I view the specific Visitor's Profile from such list, I expect it to show me full profile. Or at least it should be stated in some explicit manner, that segment was applied while generating that profile so the profile is not "full". What's your opinion guys? Personally I would vote for option 1.

Visitor's Profile Popup is disabled on Demo, but a links to start looking at that issue would be:
http://demo.piwik.org/index.php?module=CoreHome&action=index&idSite=7&period=day&date=yesterday#?module=Live&action=indexVisitorLog&idSite=7&period=day&date=yesterday
and
http://demo.piwik.org/index.php?module=CoreHome&action=index&idSite=7&period=day&date=yesterday#/?module=Live&action=indexVisitorLog&idSite=7&period=day&date=yesterday&segment=visitCount%3E%3D2