I have been using B2Evo for about a year now and recently the LiveHits plugin mapping feature stopped functioning correctly. It is putting all the markers in a vertical line. :'(
I went to the LiveHits site but no recent updates or solutions to this issue. I decided to go through the code and found and fixed the error myself. You can find the solution on my blog at http://my.wetcoastlife.com/blog1.php/2010/02/fix-b2evolution-livehits-plugin-map-api
Let me know if this solution fixed your LiveHits mapping issue.