Custom control dropdownlist - need advice

I'm building a custom control (ASP.NET 1.1 / C#) that contains a number of dropdownlists. I'm fairly new to custom controls and am having trouble understanding a couple of things. I'm adding the DDLs as part of the CreateChildControls method and binding their data at the same time but on postback these DDLs have an item count of zero again. Is it possible to persist the state of a control added in this way across postbacks? What I don't understand is that if I re-bind the DDL on postback then its SelectedIndex is set to the posted value at some point between the end of CreateChildControls and Render. Is it possible to have a custom control containing a dropdownlist which only needs to be bound once on the initial load...?

tcstom