Difference in behavior on Mac?

Hello all,

I've gotten an extension which uses LiveConnect fully working on 
Windows, including conveying error messages from Java back to 
Javascript, but when using a Mac I get this message:

"InternalError: Java class net.sf.saxon.xqj.SaxonXQConnection has
no public field or method named 'getStaticContext'.


The extension even on the Mac is in fact successfully returning a 
connection object, so I don't think it can be access to the JARs (and 
again, my simple Java wrapper class and Javascript LiveConnect code are 
the same as in the Windows extension (besides the OS detection) which 
does work fine)...

When I comment out the code causing the error above (I can do that, 
since this code is not absolutely essential), the script continues all 
right with other method calls to create another Java object, etc., but 
it has the same problem again as above later (with a different method)...

Does anyone have any ideas why this might occur, and only on the Mac? I 
just got Apple's auto-update for Java (and tested the extension before 
and after to no avail), and Apple's message said their update covered up 
to and including 1.5

Could it just be a problem with Firefox's LiveConnect on the Mac or the 
JVM on the Mac? I'm pretty new to Java, so I may be missing something 
obvious.

best wishes,
Brett