CREATE DATABASE permission denied in database 'master'

[casper]

Hi,

I use asp.net 2.0 and VWD (and sqlserver 2005 express) on windows 2000 sp4..
Starting from VWD, it works.
Starting from the browser, the code below produces this error:
CREATE DATABASE permission denied in database 'master'.
An attempt to attach an auto-named database for file C:\Documents and
Settings\Admini strator.PEN1800 \My
Documents\testf romc\App_Data\W roxUnited.mdf failed. A database with the same
name exists, or specified file cannot be opened, or it is located on UNC
share.
<form id="form1" runat="server">
<div>
<asp:SqlDataSou rce id="SqlDataSour ce1" Runat="server"
ProviderName="< %$ ConnectionStrin gs:WroxUnited.P roviderName %>"
ConnectionStrin g="<%$ ConnectionStrin gs:WroxUnited %>"
SelectCommand=" SELECT * FROM News">

</asp:SqlDataSour ce>

<asp:DataList ID="DataList1" Runat="server"
DataSourceID="S qlDataSource1"
RepeatDirection ="Vertical" RepeatLayout="F low" >
<ItemTemplate >
<div class="newsItem ">
<span class="newsTitl e"><%#Eval("Tit le")%></span>
<span class="newsDate "><%#Eval("Date ToShow", "{0:dd MMM
yyyy}")%></span>
</div>
<span class="newsCont ent">
<asp:Image style="float:ri ght" ID="NewsImage"
Runat="server"
ImageUrl='<%# Eval("PictureUR L", "~/NewsImages/{0}")
%>' />
<%#Eval("Descri ption") %>
</span>
</ItemTemplate>
</asp:DataList>

</div>
</form>
The app_data directory contains wroxunited.mdf. and has the right
permissions (IWAM_myserver has full control)

What's the problem here?
Tnaks for help
Casper