A lot of Macs from that era use nVidia AHCI mode SATA2 controllers, which have terrible compatibility issues with all sorts of drives and usually bottleneck to SATA1 or are simply flagged as incompatible by drive manufacturers with certain controllers (particularly Phison).
Sandisk normally use Marvell controllers which have excellent compatibility, but firmware development is up to each drive manufacturer so updating your drive (via SATA) on a machine using Sandisk’s toolbox would ensure your best hope of compatibility and performance.
Crucial models using those Marvell controllers (generally not the lower end models, but most older models prior to the BX200 used them, including recent products such as the MX300) should be compatible. Intel 320 drives will function with ideal reliability and full SATA2 speeds on those nVidia controllers, but you will have to dig into your specs to see if it is one of the designs I am describing.
Zapping the PRAM on your Mac may also help.