Sonnet has tested the following cards with the Drobo S:
Tempo SATA E2P..............................compatible
Tempo SATA E4P..............................not compatible
Tempo SATA ExpressCard/34...........compatible
Tempo SATA Edge ExpressCard/34...compatible
Tempo SATA Pro ExpressCard/34.....not compatible
Tempo SATA X4P..............................not compatible
Qio eSATA ports...............................not compatible
Using a Drobo S with a Macintosh and Sonnet Tempo SATA E2P, Tempo SATA ExpressCard/34, or Tempo SATA Edge ExpressCard/34. you may get a device removal error after waking up from sleep. The Drobo S will automatically reconnect. System caches are flushed before sleep, so there is not data loss.
A Lion install removes the driver for the Tempo SATA E2P, Tempo SATA ExpressCard/34, and Tempo SATA edge ExpressCard/34. Just reinstall the driver and the card will work again.