I don't know if the following is causing your problem, but it sounds familar
Ancestry has a "lite version" search browser and they have a more "detailed/robust" browser
When you search directly from FTM 2012 the system uses the light version and many times in the past everything would be going just fine when you used this light version, but for some reason sometimes the system said you are behind a firewall and it was very difficult sometimes to fix/get around that
If you searched direcly to ancestry you use the more robust version. I have never had the robust version tell me I was behind a firewall
So maybe you should try going directly to ancestry using the robust browser to register. I don't know if that will help, but it doesn't cost anything to try
Ancestry has a "lite version" search browser and they have a more "detailed/robust" browser
When you search directly from FTM 2012 the system uses the light version and many times in the past everything would be going just fine when you used this light version, but for some reason sometimes the system said you are behind a firewall and it was very difficult sometimes to fix/get around that
If you searched direcly to ancestry you use the more robust version. I have never had the robust version tell me I was behind a firewall
So maybe you should try going directly to ancestry using the robust browser to register. I don't know if that will help, but it doesn't cost anything to try