This week's book giveaway is in the OCPJP forum. We're giving away four copies of OCA/OCP Java SE 7 Programmer I & II Study Guide and have Kathy Sierra & Bert Bates on-line! See this thread for details.
The subject heading for this thread is "dispatchaction in struts" but in your post, you talk about using multiple actions? Which is it? Are you using a single DispatchAction with multiple methods, or are you calling different actions? If you're using a DispatchAction, check to make sure that the form bean is defined properly for the action. If you're using multiple actions, they should each be using the same form bean.