"I upgraded to QT 3.0, Pro edition. Now when I play Marathon (ver 1), the music does not play correct. It is harsh, scratchy, and just does not sound right. QT version 2.5 plays the music fine."
"When playing MIDI files in the new QuickTime 3, some instruments have a strange popping noise right before or after the note is played. Never had problems with old QuickTime."
One posting suggested that the cause was due directly to QuickTime's MIDI synthesizer: "Instead of passing MIDI data to your sound card's MIDI processor (of course most Macs don't have hardware MIDI support so they have to have a software synth), QT3 steals CPU cycles to mix samples from its own database and play them back like a bunch of simultaneous waves. If you try to do anything else on your CPU, the software synth doesn't get all its timeslices and cuts out."
Streaming audio/video crash Another thread discusses crashes in web browsers when playing streaming audio/video with QuickTime 3.0 installed. Here is one example:
"My computer hangs whenever I try to watch a streaming QuickTime 3 video in Netscape (both Navigator stand-alone and Communicator 4.05). Basically, the video freezes, the audio fades in and out, then the computer hangs."
Several people claimed that this will happen if you do not install the Sound Manager extension that comes with QuickTime 3.0. However, a couple of people said problems persisted even with this extension enabled.