Hi, This is completely foxing me, so I hope somebody can point to a solution. I'm trying to track down strange hiccups I'm getting in the audio chain, so I'm using the old sample-code ToneProducerApp with printouts added as needed. As I'm comparing BeOS behaviour with Haiku, I've mostly been compiling on BeOS and using that executable on Haiku too. However, tonight I tried compiling (as a user app) under Haiku, and I get the consistent error that "BBufferProducer::SendBuffer(...) is private in this context". The ToneProducer class is derived from BBufferProducer: class ToneProducer : public BBufferProducer, public BControllable, public BMediaEventLooper {... so why is this happening? (It's not my changes -- the original is the same. The Makefile is the standard BeOS form original, but of course uses the Haiku engine.) TIA, -- Pete --