Can you describe your "recent blogs" user control in more detail?
Is it only loading data when not IsPostback? What are the viewstate settings for the controls within it? It sounds to me like viewstate is turned off and that you are testing for IsPostback so you only load the data on the initial page hit. So when you do a postback from the other user control, this one isn't loading any data, nor restoring any from viewstate.
-Peter
peterlanoie.blog