Fw: De Ysalba

Dear Group,
Since there appears to be members with the surname of de Alba, I thought I'd pose the question again.
Has anyone seen these surnames used interchangably in their research? Or are they distinctly different?
Any help or opinions would be greatly appreciated.   Thank you, Alice

--- On Mon, 1/23/12, Alice Blake wrote:

From: Alice Blake
Subject: [Nuestros Ranchos] De Ysalba
To: research@nuestrosranchos.com
Date: Monday, January 23, 2012, 1:08 AM

Does anyone know if the surname de Ysalba or de Esalba is a variation of de Alba?
I've got marriage entries for Maria de Ysalba with Joseph Feliz de Arrambide 02/20/1724 and 03/19/1720 in Mexico, DF.  Yet I can't find any de Ysalba's anywhere.  Both entries from two different churches in DF couldn't be wrong?   Your help would be greatly appreciated.    Alice Blake