8 vs 24 threads at Building static raycast accelerator

i guess noone can help but lets try

I run an old 8core dual Xeon and can render a scene without problem in 2009 vray SP2 32bit
the same file fail to render on dual xeon12coreHT at “Building static raycast accelerator…”

I notice the same for SP4 x32

so far i whouldnt worry but i am in progress to remove all my old 8cores from farm
how can I get my new nodes to render such a job ? disable HT (it work without) is not an option and using x64 whould output incorrect results (for special curcimstate)

28.06.2011 19:30:15; [V-Ray] Preparing ray server…
28.06.2011 19:30:15; [V-Ray] Building static raycast accelerator…
28.06.2011 19:30:17; [V-Ray] 15 % completed.
28.06.2011 19:30:17; [V-Ray] 21 % completed.
28.06.2011 19:30:17; [V-Ray] 30 % completed.
28.06.2011 19:30:18; [V-Ray] 35 % completed.
28.06.2011 19:30:18; [V-Ray] 40 % completed.
28.06.2011 19:30:18; [V-Ray] 45 % completed.
28.06.2011 19:30:18; [V-Ray] 51 % completed.
28.06.2011 19:30:18; [V-Ray] 63 % completed.
28.06.2011 19:30:19; [V-Ray] 72 % completed.
28.06.2011 19:30:19; Error rendering frame 0: An unexpected exception has occurred in the network renderer and it is terminating.
28.06.2011 19:30:19; Send End of Job command to Max