Optiplex 780 SFF A05 SSD boots intermittently

HI,

Testing a Crucial 300 SSD. General observation is that POST is longer and sometimes no boot device found. In Setup whilst the drive is listed it is not so in the Boot Sequence. However, on next boot with F12 the drive is listed in the bootable devices and goes on to boot!

Optiplex 780SFF/Q9400/8GB.

Any ideas, anyone.

PS cannot navigate mouse in this post. IE9 beta?