I recently have run into an issue where PDM for older PIX firewalls does not load, It allows you to log in but the PDM window just does not load.
If you notice you'll see an error in the lower left of IE that says:
exception: java.lang.ArrayIndexOutofBoundsException: No such child: 0,
Here is what I found earlier today. The PIX's with 3.0 only support up to Java 1.4.2_03 and since Java end of life'd this version of Java in October 2008 it seems that they are no longer including code back that far in the newer versions of Java.
Updating to the most current version of Java will not resolve your problem with getting the PDM to load, using any other browser will also not resolved the issue.
What you must do is find the older version of Java (1.4.2_03) in my case, remove all other versions of the workstation you intend to use to manage these older PIX (mine was a PIX 501) once you have loaded only the version you'll be able to load the PDM.
I expect you'll also be able at this point to load the most current version of Java on the system, leaving the older version alone and Java should work correctly. This has been my experience in the past when older versions of Java are required for some older applications.
Link to older versions of Java hopefully it will still work when you read this:
Hope this helps someone: