Here is a very simple widget for displaying a map tip on mouse over of a layer that is a Feature type operational or basemap layer. It REQUIRES a layer that is type="feature" to work.
There are a few things I have found about using the Maptips for a "dynamic" layer when "feature" is not working. First off I can probably bet you are working with dynamic data from a SQL Server. I have been frustrated with the fact that I could not change the data to "feature" without the data not showing, but found that if you change your type="dynamic" to type="feature" just add mode="snapshot" to the layer config file. I am still having problems with speed with the maximum number of features returned from the server but I am getting closer. Let me know if this helped.
