Use of automation 'Microsoft ActiveX Data Objects 2.8 Librar

Hi,
I am trying to use a dll (msado15.dll) in a Nav object. I declare an automation variable of the type 'Microsoft ActiveX Data Objects 2.8 Library'.Command.
This type is contained in the msado15.dll.
On one platform it works; if I use Nav's built-in object browser (F5), I can see that the automation variable has a property, ActiveConnection, and the syntax for this active connection is:

[_CONNECTION ActiveConnection :=]ActiveConnection([_CONNECTION ActiveConnection])

(as shown under the "paste arguments" box)

So far so good - it is as it should be.

But on another platform, when I do the same declaration, the syntax is shown as:

[_CONNECTION ActiveConnection :=] ActiveConnection([BOOL ActiveConnection])

("BOOL" instead of "_CONNECTION")

and then it doesn't work.

The platforms are alike - both are Windows Server 2003 R2, and in both cases I use Nav 2009R2.

Does anybody have a clue what could cause the syntax to be shown incorrectly on one platform?
Thx!