Virb Edit 5.2.0 encoding slow

Virb Edit 5.2.0 doesn't use all the CPU cores and thus encodes much slower than the previous version of Virb Edit that I was using, namely 4.2.2.

I use Virb edit on a Windows 7 machine with an 8 core CPU, and all the Virb edit software versions after 5 have not been utilizing all of the CPU cores during encode.

I'm using FFMPEG for both the encoder and decoder. It appears that during encode only 2 or 3 threads are ever used, and thus the encode speed is really slow.

The same encode using version 4.2.2 runs using all cores and thus completes 3 to 4 times faster.

To reiterate, the slow encode occurs on all versions 5 and above of Virb Edit.

Does anyone have a similar issue/ knows how to resolve it?