Question about Nvidia FX 3400 and NEC AcuSync LCD 92VX

Hi,
I recently install Vista Beta 2 (build 5384 - Japanese localized 32 bit) on
HP xw 6200.

Question-A:
I noticed that the graphics performance is unaceptably slow, although
the overall rating is 4 (processor 5.4, memory 5.8, HDD 4.0, graphics 5.9).
Is this because the current driver for Nvidia FX 3400 has not been tuned
yet?
or FX 3400 is not good enough to run Vista?

Question-B:
Very frequently (once per 1 - 2 min), my screen (NEC LCD 92VX) becomes
all black and "Processing..." is shown. It seems monitor is seeking the
signals.
This does't happen with XP.
Is there a workaournd for this?

Thanks in advance,

-Sami KOZONO
Autodesk, Inc.