In PostView.ascx, are you outputting the content of the post via <%= Post.Content %> .... or are you using a PlaceHolder with an ID of "BodyContent"?
Both work, but I think rules such as only showing XX number of characters is applied when using the placeholder. Here's what the placeholder should look like:
<asp:PlaceHolder ID="BodyContent" runat="server" />
BE will output the content of the post in that placeholder. Or if it should just be XX number of characters, then it will output that excerpt instead.