Failed to allocate CPU memory Python 32bit

[freeearth]

Hello!
Sometimes we get exception "Failed to allocate CPU memory" in detect_face function.
We use mtcnn to get face boundary boxes, then we send it to model to get "embeddings" in this https://github.com/deepinsight/insightface.
Exeception occurs on face detection stage. More precisely - on n 362 - 364 lines https://github.com/deepinsight/insightface/blob/be3b7ccad3a1702f7d2baa0e1d4d0818551da93a/deploy/mtcnn_detector.py#L362
We explore, that exception disappear while we switch off mxnet multithreading (i.e. MXNET_ENGINE_TYPE=NaiveEngine)
We try on Windows-7, python both 3.6 and 2.7 32 bit.
In Oracle VirtualBox with similar parameters as in up lines, exception occurs once and after it gone away.

We opened two issues (it viewed here more widely): https://stackoverflow.com/questions/54834022/failed-to-allocate-cpu-memory-python-32bit, https://github.com/deepinsight/insightface/issues/540, but nobody answered yet.
We will great appreciate to any kind of assistance.