How to fix nAnt ASPPARSE type exists in both issue

Question

Hello, When I use nAnt to build my app I get this error:

[exec] error ASPPARSE: c:\temp\TheaterSalesOut\DemoSite\EmailInvoice.aspx(13): error CS0433: The type 'Controls_OrderView' exists in both 'c:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\Temporary ASP.NET Files\root\ab87bc79\8d2820ab\App_Web_8z8vmqbs.dll' and 'c:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\Temporary ASP.NET Files\root\ab87bc79\8d2820ab\App_Web_j_scbg2a.dll'

Is there anything I can do to fix this?

Thanks!