There is an ongoing debate on the CPUK site (http://www.cpukforum.com/forum/index...howtopic=34651) dealing with the identification of Nepenthes burkei in cultivation; and there is a current view that many held in collections (including Kew Gardens for many years!) were simply mislabeled N. ventricosa -- the species which N. burkei most closely resembles. To add further confusion, there is also a variety of color and shape associated with N. burkei pitchers.
Would others growing this species be willing to show off their photos . . .
Nepenthes burkei (Mt. Halcon -- Borneo Exotics Clone)