Problem visioviewer 2007

Hi. I'm using Visioviewer 2007 versión in a asp .net application. I
need to set the visio file dinamically.


For example. In my code I have:
....
visio.src = "visio.axd?Parameter";

....

visio.axd is a httphandlers of my application. It is defined in the
web.config:

httpHandlers
...
add path="visio.axd" verb="*"
type="GestorDocumental.Handlers.VisioHandler,Visio HandlerLib"/
/httpHandlers

Parameter is used by my library VisioHandlerLib to obtain a arraybytes
that is in a database.

This line visio.src = "visio.axd?Parameter" is ok in visioviewer 2003
version, but in visioviewer 2007 version I have this error: The
Microsoft office visio viewer cannot load the specified urd or file.

Please, I need to thow what is the problem. In version 2007 I'm not
use this sintaxis: visio.axd?Parameter?

Thanks.