500 internal server error

Hi. We are currently using oracle application server 10.1.0.2 for Forms/Reports,Discoverer, Infrastructure. Recently we have been receiving many "500 Internal Server errors Too many Open Files" when accessing an application via forms. This happens once a day and had started happening a few weeks ago. We have not made any changes to the applications or oracle software. We need to restart the OC4J BI Forms server each time.
This version of OAS uses jdk 1.4. I believe that the problem might be resolved in JDK 1.5 but not supported for this OAS version. Anybody know a fix or workaround or this problem ? Thx.:confused: