http://www.accesstoinsight.org/tipitaka ... .than.html" onclick="window.open(this.href);return false;
This may be because the buddha and his followers wanted to make clear their idea of rebirth is totally different from the hindu belief of reincarnation that existed at the time.
See also:
http://en.wikipedia.org/wiki/Rebirth_(Buddhism" onclick="window.open(this.href);return false;)There is no word corresponding exactly to the English terms "rebirth", "metempsychosis", "transmigration" or "reincarnation" in the traditional Buddhist languages of Pāli and Sanskrit: the entire process of change from one life to the next is called punarbhava (Sanskrit) or punabbhava (Pāli), literally "becoming again", or more briefly bhava, "becoming", while the state one is born into, the individual process of being born or coming into the world in any way, is referred to simply as "birth" (jāti). The entire universal process that gives rise to this is called saṃsāra.