I am currently having the exact same problems. Same symptoms. I still need to try a few things, but cloning to external drive then allows the Mac Mini to boot to that drive perfectly. When the drive is then transfered into the Mac Mini (Late 2009 like yours) I get a prohibited sign. Circle with diagonal line through it. Then, white screen with no real keyboard response. If you hold the option ket down on boot up for a long time, then you might get the the ssd drive as a boot choice, but then the boot fails.
Stange. The cloned SSD (SanDisk Ultra II 480GB) works perfectly from a USB enclosure, but once it gets installed in the Mac Mini, it fails. The Mini must not see the boot file. I think that is what the circle symbol means.
Have you had any success?
I am still trying a few more things before I install a traditional 7200 RPM HDD. Almost ready to give up.
SanDisk tech support says that the the Ultra II should work just fine.
C
