We had a major issue over the weekend.  Our sitemap was being blocked
by a proxy server that caused a 404 error every time Google tried to
crawl us. Our site was never down but Google bot was getting 404
errors from when i tried to index from our .xml sitemap.

We have now fixed the error and our site is being indexed again but
our homepage has not been indexed and in the reporting it says that
the last time the homepage was accessed it gave a 404 error.  Our
operations team set up an external computer that acted like the Google
Bot and was able to access the homepage so we don't know why it is not
being indexed.

How do i know if the 404 error is still occurring ? Is there anyway to
get our homepage crawled and indexed?

Out site's Tool bar Page Rank has stayed at 7/10 and our European
sites are still showing up in the index for our branded terms but not
our .com site.  We actually are still ranking for all terms that
didn't direct traffic to our homepage.  Is this some kind of penalty
for the 404 errors over the weekend?

Our site is a major ecommerce site that has been around for over 11
years without ever going down for extended periods of time we
shouldn't be penalize for 2 days of 404 errors.

Can you please help in any way.

Our site is AbeBooks.com

Thanks,
Sterling Simpson