Who said there were no comments from the SEC?
The SEC comments are not made public until the document goes "no further comments" or it is voluntary withdrawn or involuntarily revoked. Therefore, it can easily go automatic after 60 days, but it doesn't mean the document is clear of comments.
Most registrations take more than 60 days to clear. If the company is not able to clear all comments, the SEC will wither ask the company to voluntarily withdraw the document, or eventually involuntarily revoke it if it has gone automatically effective.