After opening 2 small sound files in my fresh 1.3.5 install, I noticed increasing delays and hard disk activity each time I clicked the "play" button. Running 'top' in the terminal revealed that Audacity was already using an RSIZE of 2GB! When opening a 128KB mono WAV file, RSIZE goes up with about 120MB, and every time I click "Play", about 80MB goes down the drain. After a while the swapping becomes so excessive that the program becomes unusable. It seems that some very important free() or delete calls were forgotten in this version. I'm going back to 1.3.3 for the time being...