InfoPath Dev

Hi, I am having a strange problem with attachments field on a list InfoPath form. The attachments get uploaded successfully but not able to access/open any attachment uploaded by someone else, on the form. The error says "The file is corrupt or invalid". It is happening for all the file formats...

I want to hide the ribbon, create a submit button on the form (done) and after the submitter clicks the "submit" button, the submit button disappears (done) and the save/update button appears and stays for all future updates to the form (need help with this part)

I am a new InfoPath user. I don't have a computer science/IT background. I just started using InfoPath 2007 to automate our complex contract formulation process that has lots of inputs and alternate clauses. I copied the basic (required) contract structure/format from Word, which has hyperlinks and...