WebResource.axd issue

Question

I have an issue where my webresource file is creating a query string that has an & instead of & e.g. ?d=SV_oUGD_hObZCctAvsB2_mHN0SUaqQJnMCqXLIafAmw1&t=633644501520000000 Can anyone point me in the right direction to fix this as this code is being generated automatically by my web.config file. Other controls in use seem to be use the correct encoding and not cause W3C validation errors.