#8 causes NaNs almost immediately during training

[craffel]

If I run the TensorFlow version of this code (tf_train.py) with https://github.com/openai/iaf/pull/8 applied, I get a NaN within the first few iterations and training stops. If I remove that change, training proceeds fine. @pukkapies were you ever able to get the model training appropriately with your changes applied? If so, what hyperparameter settings were you using?