Java SE (Java Platform, Standard Edition)

Please help,

I am preparing an interim release of a client project and am encountering an exception when JWS processes the jnlp file. The sequence of events is as follows:

I request a .jsp page which displays a form. The action of the form is defined as "<%=appContext%>/app/filename.jnlp" and the method as "get". I select the submit button for the form. The .jnlp file is downloaded and JWS is invoked to open it. A "Download Error" dialog box is displayed with the message "Unable to Launch Application". Selecting the "Details" button of this dialog displays four tabs "General", "Launch File", "Exception", and "Wrapped Exception".

General:
An error occurred while launching/running the application.

Title: Application Name
Vendor: Vendor name
Category: Download Error

Unable to load resource: http://host/NASApp/webapp_name/app/filename.jnlp

Launch File:
The entire launch file is displayed and is as expected.

Exception:
JNLPException[category: Download Error : Exception: java.net.SocketException: Unexpected end of file from server : LaunchDesc: null ]
at com.sun.javaws.cache.DownloadProtocol.doDownload(Unknown Source)
at com.sun.javaws.cache.DownloadProtocol.isLaunchFileUpdateAvailable(Unknown Source)
at com.sun.javaws.LaunchDownload.getUpdatedLaunchDesc(Unknown Source)
at com.sun.javaws.Launcher.downloadResources(Unknown Source)
at com.sun.javaws.Launcher.handleApplicationDesc(Unknown Source)
at com.sun.javaws.Launcher.handleLaunchFile(Unknown Source)
at com.sun.javaws.Launcher.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)


Wrapped Exception:
java.net.SocketException: Unexpected end of file from server
at sun.net.www.http.HttpClient.parseHTTPHeader(Unknown Source)
at sun.net.www.http.HttpClient.parseHTTP(Unknown Source)
at sun.net.www.http.HttpClient.parseHTTPHeader(Unknown Source)
at sun.net.www.http.HttpClient.parseHTTP(Unknown Source)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown Source)
at java.net.HttpURLConnection.getResponseCode(Unknown Source)
at com.sun.javaws.util.URLUtil.doesURLExist(Unknown Source)
at com.sun.javaws.cache.DownloadProtocol.doDownload(Unknown Source)
at com.sun.javaws.cache.DownloadProtocol.isLaunchFileUpdateAvailable(Unknown Source)
at com.sun.javaws.LaunchDownload.getUpdatedLaunchDesc(Unknown Source)
at com.sun.javaws.Launcher.downloadResources(Unknown Source)
at com.sun.javaws.Launcher.handleApplicationDesc(Unknown Source)
at com.sun.javaws.Launcher.handleLaunchFile(Unknown Source)
at com.sun.javaws.Launcher.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)

The environment is iPlanet App server 6.0 on Windows NT with IIS acting as the webserver. I've tried this with both IE and Netscape 6.2.1.

Thank you for your help.