mysterious trailing slash google webmaster central errors

Hey all,

My pages and posts don’t end in a trailing slash.

They’re e.g. http://www.example.com/about

My sitemap lists the pages and posts without trailing slashes.

I’m getting google webmaster central errors for

http://www.example.com/about/

I have the feeling this is something to do with wordpress auto redirecting from about/ to about???

Can anyone help me figure this out?