Many errors like ambiguous in the namespace on build

I am trying to build my first significant try at a complete ASP.NET site using VWD and not get a bunch of error messages when I try to build a page or the web site. I did not make any fundamental changes in the site and restored a copy of the site but get the errors about objects being ambiguous.

IT appears that there is something outside eth actual web site directory affecting this. I have tried to delete the temporary files to no avail.

Where else should I look to correct my error? My searches here didn't help me find anything that appeared relevant.

Thanks a lot.

A sample of some of the 27 errors listed by VWD are below:

Error 1 'STCOCMaster' is ambiguous in the namespace 'ASP'. D:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\Temporary ASP.NET Files\stcoc\07133919\1b65f3de\App_Web_zgdwkvvm.10.vb 47

Error 2 'STCOC' is ambiguous. D:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\Temporary ASP.NET Files\stcoc\07133919\1b65f3de\App_Web_zgdwkvvm.8.vb 106

Error 3 'STCOCMaster' is ambiguous in the namespace 'ASP'. D:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\Temporary ASP.NET Files\stcoc\07133919\1b65f3de\App_Web_zgdwkvvm.8.vb 121

( Errors 4 through 26 omitted as they seem very similar to those above )

Error 27 'CreateResourceBasedLiteralControl' is not a member of 'ASP.STCOCMaster'. G:\STCOC\VSWeb\Admin\ADMIN.master 1

Its likely that you have multiple definitions for STCOCMaster!. Check your classes for the definition of the STCOCMaster as the errors are self explanatory!

Thanks

Thanks for the reply, e_screw. I had thought the errors were clear and had searched for duplicate definitions of the STCOCMaster but found none. As it turned out, another class was a duplicate and that was the problem so you pointed me in the right direction.

The thing that confuses me in this situation is that the duplication has been in the site for a multiple versions over the last couple of weeks which is why rolling back to my last known 'not bad' version failed. So, I had an invalid class definition that was not failing until a couple of days ago.

Thanks again!