Access denied to write in folders

Hi all,

I have a asp.net 4.0 application that create PDF files with ITextSharp and upload files. The application also use authentication forms. In my Web.Config I create the security rules for authorization and authentication. When I test the application in my machine, all works perfectly, but when I publish the application and try to upload files or create PDFs the application send me to login page, as if the user not have permisions to access this folders. My ISP use impersonate.

The Upload folder are inside "Contenido" Folder.

The PDF Folders are in root.

Can someone help me?

Here I show part of my web config.

<authentication mode="Forms">

<forms name=".BiaPlussAUTH" loginUrl="~/Default.aspx" protection="All" path="/" timeout="2880"/>
</authentication>
<authorization>
<allow users="*"/>
</authorization>

<location path="Contenido">
<system.web>
<authorization>
<allow roles="OPER, OWNER, SUPER, CONF"/>
<deny users="?"/>
</authorization>
</system.web>
</location>

<location path="PDFBia">
<system.web>
<authorization>
<allow roles="OPER, OWNER, SUPER, CONF"/>
<deny users="?"/>
</authorization>
</system.web>
</location>

<location path="PDFBia">
<system.web>
<authorization>
<allow roles="OPER, OWNER, SUPER, CONF"/>
<deny users="?"/>
</authorization>
</system.web>
</location>

The user which I Connect has "OPER" Role