Looping rebuild of toolbox part

I recently had an issue that brought me to a stop for a whole day.

My assembly had several sized of pem hank bush in it and quite a few instances.

Suddenly with every little action the hank bush started rebuilding through all its configuarations and Sw effectively froze until it was completed.This made he system unuseable.

With help from my VAR we did so many things with copying and replacing the tool box that its hard to say what cured it. But none of the replacing the toolbox and copying the parts in it seemed to have cured it, and it occurred in new assemblies once that toolbox part was inserted.

The last things I did before it stopped was I deleted all the toolbox components from the assembly and then it was ok.

Then I restored the previous version from PDM so they were all back again and it continued to be ok.

The assembly was sheet metal containing parts generated as a multibody assembly.

The toolbox is in my PDM (std).

I am working with PDM remotely over a VPN.

I wondered if anyone had anything like this before?

SolidworksGeneral