I need to have two required fields as lookup input field (one for account and one for contact) in a single pageblocksection section. On selection of each lookup, a particular section is getting rendered. When there is only one required field, both the rerendering is happening properly. When I make both the fields required, the first lookup selection rerendering is not happening (which ever I chose first) I have no idea where is the problem. Please help. Thanks,
I found the issue and the solution at https://developer.salesforce.com/forums/ForumsMain?id=906F0000000965kIAA
Only when I clubbed the two required input fields for action into two separate action regions, the re-render happens as expected.