From the closed thread and other threads, I gathered these six ideas, none of which work, as explained:
1. Install Windows version of Drive Manager on an Intel Mac with Parallels and use it to adjust the sleep setting. I have a G5 (non-Intel) Mac, so installing Windows is not an option. I don't have Parallels or an extra copy of Windows and wasn't planning on buying them to support these drives. The Mac version of Drive Manager has no sleep setting.
2. Disconnect drive from eSata cable and connect via USB; then use Drive Manager to adjust the sleep setting. Again, the Mac version of Drive Manager has no setting for "Adjust Sleep Interval".
3. Try a program called HD Awake. I tried it; it doesn't work.
4. Connect the drive to a Windows computer and use the Windows version of Drive Manager to set the sleep interval. My drives are formatted to Mac OS Extended, so they can't be read by a windows computer. They have lots of data on them, so reformatting them to NTFS is not a practical option.
5. Install the updated FA Desktop software for Mac -- that software will divert the "responsibility" for setting the sleep interval to the MacOS operating system rather than the FA software. I asked (and mrdenis asked) above how it diverts responsibility to the Mac OS because, as far as I can tell, it doesn't. I can't find a setting anywhere that affects the sleep time of FreeAgent drives.
6. Buy another brand that is Mac compatible. Not a practical solution now; maybe next time. I thought these were Mac compatible.