Macintosh bootable volumes are supported on the internal 2-port PCI card (part number TSATA) but are not supported on any of the other SATA cards at this time.
Sonnet has isolated the occurance of drives not mounting in 10.7.4, which occurs only in 32-bit mode with the Tempo SATA E4P, E4i, and Tempo SATA Pro ExpressCard/34. Users running in 64-bit mode will not experience any issue. (To boot in 64-bit, hold down the 6 and 4 keys when the Mac starts up.) Install driver 2.2.9 or greater to fix the 32-bit mode issue.