File/Printer Sharing

I recently purchased a new MBP/Retina with Mavericks. I also own an iMac desktop with Mavericks and I configured it to allow File Sharing and Printer Sharing (via an Apple Airport) and it's really slick. However, when the iMac goes to sleep, Bonjour will not wake it. The MBP denies that the iMac exists. I run upstairs, tap the iMac spacebar and all is good again.

I experimented with the System Prefs on the iMac and the culprit is the computer sleep selection (in Energy Saver). If I set it to "Never," the problem does not exist. If I set it to anything other than "Never," the problem occurs at whatever time I set for the computer sleep. According to Apple, Bonjour should wake the iMac.

I tried all three resets (soft, hard, and factory default) on the Airport but it made no difference.

Just for the record, all software is up-to-date.

Ideas?