tedster - 2:14 am on Jun 4, 2010 (gmt 0)
do i need to be concerned with #1 in terms of Google ranking?
If Google can't retrieve a page for an extended period due to DNS errors, then yes, that certainly can affect ranking - or even toos the page oput of the index. Check your server logs and see if googlebot has requested the problematic URL recently and received a 200 OK response from your server. If you see that happening, then the error is in Google's report, not your site.
But, since a third party report also highlighted a DNS problem for you, I certainly encourage you to fix it.