As a work-around, Jon suggested trashing the preferences for Monitors & Sound and Display. This worked. A soon-to-be-released Sleeper 3.0.1 will permanently squash this bug.
IDE CD-ROM drive disables Sleeper On a related front, Dana Leighton, using a StarMax clone with an IDE CD-ROM drive, found that Sleeper would not work at all, after updating to 3.0 and Mac OS 8. Conflict Catcher claimed that the problem was due to Apple's CD-ROM extensions. Once again, Jon Gotow came through with the explanation:
"Yes. The IDE CD-ROM is causing problems. I'm working on a fix. Just to let you know the details: When Apple first wrote the ATA Manager to deal with IDE drives, the programming interface only specified support for one IDE device, and Sleeper was written to this spec. Since then, they've introduced the Tanzania II motherboard (that's the one, isn't it?), with both an IDE hard disk and CD. Once Sleeper recognizes that the CD is distinct from the hard drive, we shouldn't have a problem."
By the way, if you do download Sleeper, be sure to check out its FAQ file. There is a wealth of useful troubleshooting info in it.