AIF Web Services update method

Dear All,

I have installed and configured AIF web services on IIS for Axapta 2009. I published InventItemService and consumed it in C# application.

The item creation is working fine after passing all the Axd documents.

I updated document service to include update method and overridden the update method of AxdBase class in AxdItem Class. After passing data to update method of service in C# app then unknown exception is thrown as "An unspecified runtime engine error has occurred. Error code: %d." 

Is there any other way to handle update or i am doing something wrong here. Please help me on this.

Thanks,

Sayeed