I did a restart of game launched from impulse then was able to build again... not sure if impulse was the trick or not at this time...
just finished test from launching from desktop icon ... I was able to build.. so load through impulse make no diffidence..
secnario was game got sluggish during battle exited out after battle over.. reload and could not build got this message.. "can't build: harvesting this resource requires additional technology." then exited and reload through impulse game was working again.. exited game and restarted from desktop icon and game still worked fine.. here is save file though not sure will help now...
http://dl.dropbox.com/u/8792236/tfw5.EleSav