Hi, I have a little Problem: I'm using OpenGL in my Program, in combination with OSS via portaudio. The Updates of the OpenGL display are triggered by the audio callback, protected using the available Methods of the GUI-Toolkit that I use (fltk). And I'm experiencing very strange effects, like: without Audio the OpenGL works fine. without the OpenGL, the audio works fine, however when used in combination, the Audio Thread (callback) stops very soon, and I have no Idea why? I used efence to discover wheater I'm screwing up memory somewhere, but I couldn't find anything. I ran valgrind, but it couldn't find something helpful either. I ran it from within gdb, but the program behaves correctly if run from gdb (heisenbug?). It even works better whenever I insert some cout's for debugging purposes. in gdb it also reports a signal like this when initializing the openGL, but I believe that might be propably unreleated. http://music.columbia.edu/pipermail/linux-audio-user/2004-October/016821.ht… BTW. I'm running an unmodified ubuntu warty. Any tips or pointers?? Thanks Richard PS.: (writing this message led me to some more experiments ;) ) I'm fairly sure that something is screwed up within thread syncronisation, because I can "fix" it by inserting a usleep() call at a certain position, but I do have a fairly hard time imagining what could be wrong. I'm considering to switch to blocking IO for Audio because, latency and stuff is not really an issue.