Google Webmaster Tools Reporting 404's

In the last couple of weeks I have noticed that Google Webmaster tools is reporting a lot of 404 errors under Diagnostics -> Web Crawl (around 600 in total)

I have checked a good random selection of the URLs it is having a moan about and all of them are working links. However they all have one thing in common, they are all post links, e.g.

http://www.mysite.com/118482-post66.html
http://www.mysite.com/161967-post58.html

Does anybody have any ideas as to what might be causing this?

Also while we are here, why does Webmaster tools complain about URLs restricted by the robots file, in my robots I block arcade.php and this appears in the diagnostics tab as an alert.

Seems to be a problem with including the showpost link. Please disable that option in your sitemap settings. Then you need to remove all files ending in .gz in your vbseo_sitemap/data folder and regenerate.

Inclusion of showpost pages has been disabled for some months.

I have just checked the current urlslist.txt file generated by the sitemap plugin and this doesn't contain any showpost links, however I have done as suggested and deleted the gz files.

Not sure if this is relevant or not, but I currently have the "replace post number with permalink" option enabled, on checking this does not have a nofollow declaration, however the link is anchored so this is problem irrelevant

Please disable Include Showpost Pages option in vBSEO Sitemap Generator settings , delete all your existing xml.gz extension files within vbseo_sitemap/data folder , regenerate your sitemaps.

Originally Posted by Mert Gökçeimam

Please disable Include Showpost Pages option in vBSEO Sitemap Generator settings , delete all your existing xml.gz extension files within vbseo_sitemap/data folder , regenerate your sitemaps.

As mentioned above I have done that and now show post URLs appear in the generated sitemap files. In fact the showpost exclusion has been enabled for some months now.

It seems that google is finding the showpost pages through their normal crawling.

These may be the pages Google oldly indexed and checking their existance currently.