Importance:
Medium
GG explains that reverse DNS does not affect Googlebot's ability to crawl a page.
GoogleGuy Says: [
Link to quote]
Reverse DNS not working won't cause problems for Googlebot--if it did, then we couldn't crawl lots of the web, because many people don't configure this, or do it incorrectly.
We only need to be able to map hostname->IP address.
Hope that helps,