Alpha Blending

Hey all, I have a quick alpha blend problem... (prolly something stupid I''m overlooking) I have a blended object that rotates about its own origin... When it rotates, it will be blended perfectly until some threshold (theta) and then the blending will stop working properly and it will display as completely opaque until some other threshold (phi). Am I forgetting to do something? My blend func is. GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA THanks for the help, LR