Signature namespace prefix

Hi,

i am signing XMLs:

....code....

MyXmlElement=MySignature.GetXml()

and i obtain the famous "<Signature xmlns=http://www.w3.org/2000/09/xmldsig#>"  etc...

How can i obtain "<dsignature xmlnss=http://www.w3.org/2000/09/xmldsig#>" ?

(Note: before ComputeSignature() it is not possible making changes, you know)

I'm very tired surfing for all over the web.

I will pray for a solution (i'm been reading in a lot of forums, etc) haha.