From the Mac-PCI mailing list, a reader writes: "After a system startup or restart, the sound volume is at its minimum level. The controls in the control panels and Control Strip reflect the proper volume setting, but the sound coming out of the Mac is very quiet. Using the control panels or Control Strip to change the sound volume does set the sound level correctly, but after a restart, the sound is quiet again." Others confirmed this issue.
Oddly, another reader had almost the exact opposite problem: "The same thing is happening to me (on a 7500/604 running 7.6.1), except that the sound is all the way to maximum. I've thrown away the prefs, turned down the volume, restarted, and still get maximum volume as a default." Greg Wendt emailed me about the same problem.
As is often the case, not all users (not even all PCI Mac users) may have this problem. Exact cause still is undetermined. However, Guido Bertoncini claims that some sound increase problems may be linked to using AD Online 3.0 modules with sound settings.