1394A external device can't be recognized

techo

hi All,
+ N4 N* Y* e2 f6 g+ r# n9 n: `
! }" {4 c% I, Y( N, his there any one had experienced 1394A external device can't be recognized under OS?

I encounter this kind of issue recently.

: s$ n+ a1 X0 ?: Z. K& \3 [5 \OS is Vista & XP.

1394A controller is Ricoh.
) J% d4 ], _5 P+ b7 E" W( _8 g
the situation is I could see the removable icon shown on the system tray but there is no device in OS device manager.
" _4 e6 V+ X8 ^& F7 W
indeed there are some differents but I don't know why.

I wonder it's caused by BIOS but how to prove it?
  ?# k/ s4 Q/ i0 H3 o3 K
" V  S) b, U% ?* _* ?is there any spec or document could let me refer to?

Thanks anyway!