Pooled Regression with no values in some regions

[eviewsuser]

I an doing Pooled Regression with data stacked down. Out of the 6 regions I am modelling the following regional issues:
1) One region is 0 throughout the model
2) One region has the product (my kpi) delisted mid way through time
3) One region gets the product listed only halfway through time.

Since my data is stacked down and I am doing about 4 different models using the same data I cannot change the data for media etc which are independent variables. But for the kpi itself I have blanked out the numbers where the product is not in the market. This has worked fine for the region which has no product in the entire period. But for the other two I am getting sales predicted even though the volumes are blank.

Can you please advise how I can fix this issue in Eviews?

Thank you

[EViews Gareth]

Perhaps you could explain that in a bit more detail.