I’ll be honest, I am pretty technical, but I simply do not fully understand the issue here.

Franz Enzenhofer posted a thread at Google Webmaster Help claiming Google cannot access his XML Sitemap no matter what he does. After much debugging and testing, he wrote a blog post explaining why he and maybe your servers won’t serve up your XML sitemap file to Google.

He wasn’t able to see a GET request by Google, so he dug even deeper and noticed an issue at the TCP/IP level. He said, and I quote:

You realize that googlebot makes multiple (we counted up to 11) GET requests in one single TCP/IP connection. (which is OK according to the HTTTP 1.1 spec).You realize (with the help of stackoverflow) that these multiple GET requests in the some TCP/IP connection are processed in sequence (one after the other).You realize that if one these GET requests has a major time lag (is much slower than the other GET requests) Google cuts the TCP/IP connection.Because all the GET requests in the connection were processed in sequence, all the GET requests after the cut are lost. You don’t see them in the error/access logs as they were never processed, even though they were sent.You see an error in Google Webmaster Tools, without a trace in your logfiles.

Google’s Matt Cutts commented on the blog post saying, “Interesting–good find.” He didn’t necessarily confirm this is a Google bug but JohnMu commented in the Google Webmaster Help thread implying that GoogleBot is stopping after some time due to his server speed? At least I think that is what he is saying:

Forum discussion at Google Webmaster Help.