Hi holiday,
you are not alone. I’ve the same problem with a complete other setup too (Toshiba X200 with Intel ICH8 Southbridge).
I think the problem is caused by the chipset not being able to understand the SATA3 interface standard. So the SSD tries to send SATA3 commands first, then falls back to SATA2 after the soft reboot. Had the exact same problem with an old PC and a newer HDD. Thankfully the hdd had a jumper for setting SATA1 mode and this fixed the problem.
So it would be nice when Sandisk would release a tool for setting the SATA speed permanently. Other manufacturers like Crucial did this already.
