Overflow in VBScript invoked via SOAP

We are using web services to invoke a Visual Basic Script in our server (V7).

If we invoke the Script from Windows (by double clicking it) with the server running the script runs fine.

However if we invoke it via web services we get the following error:

Windows Scripting Erorr!

Error Number: 6

Error String: Overflow

The error comes from a line that does some simple mathematic arithmetic. There is no division by 0 and as i mentioned this executes fine if invoked by Windows rather than IDS.

Is there a memory limit when executing VBScript via SOAP or some other restriction that we are not aware of.