EA with Custom Indicator: no values

Hi guys!
I am facing a strange thing (or better I cannot handle this!).
I am trying to convert a my custom indicator, perfectly working, into an EA. I have set the iCustom function as follows:
double vwp_up=iCustom(_Symbol,0,"VWP - Price",1,0);
double vwp_down=iCustom(_Symbol,0,"VWP - Price",0,0);
Commenting those variables, to see their value, I get only random allocation numbers: 2147483647. Furthermore those values are constants and do not change over time (while back testing).
So it is impossible to trade! If I stop the backtesting, strange thing, in the indicator window I get and see "vwp_up" and "vwp_down" values and lines. Here is a pic.

How can I handle this?
Thanks!

That's not a random number ... This value = EMPTY_VALUE

Ok, I did not know it was the EMPTY_VALUE constant. I set shift = 1 and indicator works but it opens continuously orders! Cannot figure out why!

I solved it... Thank you very much!