I am having problems hearing any audio at all on my Mac G5 PowerPC. I am using the MBox Pro 2 as my audio interface and it has two external studio monitors hooked up to it. The sound either isn't there or it is popping a bit. I have tried restarting my computer but it only helps now and then. It just recently started happening. I am using OSX 10.4.11, is there an update that I don't know about that I need? Can anyone help?