Server.UrlEncode apostrophe(') in Firefox

So I have a Hyperlink:
<asp:Hyperlink id="lnkTwitter" runat="server" Target="_blank">post on twitter</asp:Hyperlink>
And I'm trying to set the url in the code behind:
lnkTwitter.NavigateUrl = string.Format("http://www.twitter.com/home?status={0}", Server.UrlEncode("I'm Steven"));
When I do that and hover over the link, the url displays correctly in the status bar as http://www.twitter.com/home?status=I'm+Steven, but the actual url, if I click on the link or look at the link's properties, is http://www.twitter.com/home?status=I%27m+Steven.
For some reason, this only happens in Firefox; in IE, I am taken to the correct url.
 
 
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