Website Is Sending Wrong HTTP Headers?

This has been bugging me for a while now. Whenever I try to share my website link on Facebook or another link-sharing site, the link-sharing site either removes the URL (like it doesn't recognize it as valid) or in Facebook's case - it can't retrieve meta-data automatically.

I'm pretty sure that it used to work. However, Googling / StackOverflowing for this problem is a difficult task, since I have no idea what possibly could create this problem.

I've tried to create a static .HTM file on my website, and that works fine: test.htm

My default home page is a classic ASP (yeah I know, PHP version in the works) which uses IIS 7 URL Rewrite module.

I've tried to check the resultcodes and headers for both test.htm and my default home page on this page: [URL]

This is the results:

test.htm

URL=http://www.orango.nu/test.htm
Result code: 200 (OK / OK)
Content-Type: text/html
Last-Modified: Fri, 04 Feb 2011 10:16:55 GMT
Accept-Ranges: bytes
ETag: "0d877a654c4cb1:0"
Server: Microsoft-IIS/7.0
X-Powered-By: ASP.NET
Date: Fri, 04 Feb 2011 10:40:08 GMT
Content-Length: 452

default home page /

URL=http://www.orango.nu
Result code: 200 (OK / OK)
Cache-Control: public
Content-Length: 13463
Content-Type: text/html; Charset=UTF-8
Accept-Ranges: bytes
Server: Microsoft-IIS/7.0
Set-Cookie: ASPSESSIONIDSCSADCAR=DLPBECCBGDJMADLEPMOMHDDC; path=/
X-Powered-By: ASP.NET
Date: Fri, 04 Feb 2011 10:24:22 GMT

The first 4 lines of my default.asp (/) file are:

Response.ContentType = "text/html"
Response.AddHeader "Content-Type", "text/html;charset=UTF-8"
Response.CodePage = 65001
Response.CharSet = "UTF-8"