I've transferred many blogs from blogger to wordpress and have never received the following error (i am also unable to upgrade wordpress through the dashboard.) Don't know if it's a hosting issue or WP.
Something went wrong. If the problem persists, send this info to support:
HTTP/1.0 403 Invalid AuthSub token.
Content-Type: text/html; charset=UTF-8
Date: Tue, 10 Aug 2010 00:16:17 GMT
Expires: Tue, 10 Aug 2010 00:16:17 GMT
Cache-Control: private, max-age=0
X-XSS-Protection: 1; mode=block
<TITLE>Invalid AuthSub token.</TITLE>
<BODY BGCOLOR="#FFFFFF" TEXT="#000000">
<H1>Invalid AuthSub token.</H1>