Incorrect Registration of MSJAVA.DLL 5.0.3810

[LarryD]

We have a third-party web-based application that is used on thousands of
workstations within our organization. Beginning within the last month are
so, we have seen a new error arise when the user accesses a Java applet
that is part of this application.

The applet does not execute, the IE status bar shows an alert with an
'Error on page', and the error shows (when clicked):

Line: 105
Char: 100
Error: Unspecified Error
Code: 0
Url: <URL of the page>

We have tracked the source of the problem to an inconsistency between the
registration of MSJAVA.DLL and the version of the file that is actually
out there. The file version is 5.0.3810 but the registry shows 5.0.3805.
Installing 3810 or copying over the 3805 version of the DLL both correct
the problem.

The question is, how does this happen? We'd like to prevent it from
happening in the future. So far, it's only happened to a small handful of
users out of several thousand.

WinXP Pro SP1 (not 1a, I am assured).

Any thoughts on helping solve this mystery are greatly appreciated in
advance.

LarryD