> 192.168.1.19 - - [01/Mar/2010:10:42:33 +0800] "GET /myweb HTTP/1.1" 301 178 "-" "Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.1; Trid
> ent/4.0; .NET CLR 2.0.50727; .NET CLR 3.0.04506.648; .NET CLR 3.5.21022)"
nginx seems to be issuing the 301 HTTP redirect redirect, notice the 301 after the GET.
What's your URL after you go to http://domain/myweb and get the error? According to that log you've received a redirect and it should have changed to http://domain/myweb/. Does it show domain or localhost? You're using localhost as the server_name, I'm not sure if maybe nginx is using that domain to issue the Location on the redirect. If you're testing this from a different machine than your server it will sure fail.
Please try with the LiveHTTPHeaders Firefox plugin and tell us what Location: are you being redirected to on the HTTP 301.