Pixelated gridlines when using mapped artwork.

I am trying to make a globe using a Equirectangular Vector Globe and a set of grid lines using the grid tool.

I set everything up and set it all as a symbol.

Do my half circle and revolve it, map the art work and size to fit.

However when I look at my grid lines at 100% they are pixelated. At 300% they are not.

ANy ideas what may be causing this?

I can get screen shots if needed to explain further.

Thanks in advance.