WebMethods, sends to wrong address (activities.aspx.aspx)?

I'm verifying e-mail address using WebMethods, however, I'm getting a 404 not found (error console) saying that it can't find activities.aspx.aspx. I am using URL-Rewriting, but I tried adding a detect for 'activities.aspx.aspx' and redirect back to .activities.aspx' but it didn't do anything.

Here is the error:
[HttpException]: The file '/activities.aspx.aspx' does not exist.
at System.Web.UI.Util.CheckVirtualFileExists(VirtualPath virtualPath)
at System.Web.Compilation.BuildManager.GetVPathBuildResultInternal(VirtualPath virtualPath, Boolean noBuild, Boolean allowCrossApp, Boolean allowBuildInPrecompile)
at System.Web.Compilation.BuildManager.GetVPathBuildResultWithNoAssert(HttpContext context, VirtualPath virtualPath, Boolean noBuild, Boolean allowCrossApp, Boolean allowBuildInPrecompile)
at System.Web.Compilat ...