Once in a while when I "save as" then publish site I get message that it could not be saved (I forget exact wording and not sure if it's in same way as you). I panicked first time or two.. but after site published I just saved the vnu with same name as I had before. Just to make sure all is same I publish site again and check that all looks right.

Thanks guys. So far, so good. I'm off to post a new question now. One site was not enough for me. Now I'm getting ready to publish another one!