Name Space errors

I was trying to use the .Net version with a .Net App I have written.
And I keep getting Errors like

The type or namespace name 'data' does not exist in the namespace 'System' (are you missing an assembly reference?)

This seems to be because there is a clash between the
<add namespace="System.data"/> in my web config
and the
using System.data;
In your code

I spent hours yesterday trying to modify the source code to yet around this and its just to big a job.
So I tried the asp version which told me

Unable to find an image manipulation component

So I downloaded and ran the wizard and at step 17 it threw

The type or namespace name 'data' does not exist in the namespace 'System' (are you missing an assembly reference?)

Any advice?
I would rather solve the 1st problem and use .net but taking the name spaces out of myweb.config isnt an option.