when loading user controls dynamically, problem on postback

[sonic_soul]

basically im using a usercontrol to load other user controls, but
cannot read their user input on postback.

im using this LoadControls user control in order to load 4
different controls onto my page into panels.

<my:control>
<aspanel id="ECertificatePanel" runat="server" />
<aspanel id="BillingAddressPanel" runat="server" />
...

my problem is this:

in my LoadControl OnLoad, i only load theese controls if !IsPostback

however, when the page is being posted, the controls OnLoad events are
not being hit.

if i remove the !IsPostback constrain, and load those controls every
time.
I am guessing postback loads a fresh copy of the control and user
input is lost.