Msg#: 4535510 posted 2:43 pm on Jan 14, 2013 (gmt 0)
I'd do some digging to eliminate any possibility that another program or user error have created the errors. So if they're in GWT then either Google found links to them on your site or you told Google they exist. Have you used a link sniffer to find out what/if pages link to these URLs? Are you using any automated tools to generate an XML file for Google to read and if so have you looked at the XML file?
Msg#: 4535510 posted 5:35 pm on Jan 14, 2013 (gmt 0)
Try using a sitemap generator or other website crawler to index your site. Should be able to identify whether or not those URLs are indexable via your site and if so, what pages link to them. From there you should be able to resolve the issue easily enough.