Micro SDHC card won't mount on Sylvania SYNET7LP-DS
I also have the same tablet. I just installed a 32Gb micro sdhc and it worked right off the bat. It came pre-formatted, I installed it with power off, and on power up it was recognized and mounted.
Polaroid 32 GB CL10 micro SDHC Flash Memory Cards for Tablet PCs and Smartphones (P-SDU32G10-EFPOL)