I had this problem in Windows 7. I went to the control panel and clicked "Java (32-bit)". A window pops up called "Java control panel", I clicked the "Java" tab and the "view" button. A window pops up called "Java Runtime Environment Settings". On the user tab in my system I have two versions installed: Platform 1.6 and platform 1.7, I unticked the "enable" tick-box on Platform 1.7 and clicked "OK". I restarted my browser and was able to access the oracle forms. Hope that helps.
Oracle Jinitiator 1.1 8.2 For Mac