Timeout error for irradiance map

[Moko3D]

Really annoying endless dark bucket problems with a larger DR scene (60mill polys). 10 nodes plus host - several nodes will output dark buckets, never consistently any particular node, just a few of the nodes on every reattempt.

Error messages typically multiple:

Error receiving irradiance map X: [VUtils::VRayRenderer::getRenderData] sendClientMessage() failed [Thread::sendMessage] No response received for the specified timeout of 50000
warning Render host blah is not responding

Why so many render host timeouts on a 1gb/sec network? (see this error constantly on nearly all DR jobs even when rendering is fine and no darker buckets problems)
Where are the timeouts specified?
Can I set the timeouts to allow longer so there are less problems?

farm is working fine on smaller scenes, DR, frame by frame, RT and RT DR - just the big scenes, especially with a lot of foliage and or fur.

[svetlozar.draganov]

I don't know if there is a option to specify the timeouts, most likely they are hard-coded.
Does the issue only occurs when using Irradiance Map? Would it be possible to run another test but switch IM with Brute Force to confirm that IM is the main suspect?

What are the CPU/RAM/Network utilization during the rendering of the large scenes? If everything works fine on smaller scenes and collapse only on complex ones it is a sign for hardware issues as well.

[Moko3D]

After trying a lot of things we had to go to Brute force as the only way to get the renders done. Brute force is slow so we still have a lot of renders to get through though.

[svetlozar.draganov]

What about pre-calculating IM-caches locally and loading them from file when submitting the rendering to the render farm?

Also is there a chance to send us one of those complex scenes for investigation? There might be a bug after all.
What are the exact versions of V-Ray and 3dsMax that you are using?