OPC readValue() array item null value return

Hi All,
Im trying to read data from OPC conection in a script function. The source data is an array, I am giving the correct item path, but if I run the script it freezes the client for a while and at the end none data is read from the source.
No error comes out, just no data with unknown quality (return object: [null, Unknown, Tue Sep 02 18:19:54 ART 2014]).
This does not happen when I try to read a item linked to an tag, for example and OPC tag or and item in an Data Type instance.

Any help please, Thank you

I hope you have understand my issue,