Checkout your submit button, I mean if it is going to the server side (doing a postback) it's because you have an input type='submit', try changing that button to NOT submit.
jQuery works on client-side so it is not running a submit itself, I think you are doing it with the button.
For example:
<input type="submit" onclick="return ValidateForm();">
or
<asp:Button id="btn" runat="server" onClientClick="return ValidateForm();"/>
javascript:
function ValidateForm()
{
var isValid = false;
isValid = //Your jquery validation
return isValid;
}