[Exist-open] Mysterious error when XQuery page uses XSLT

[Thomas W. <tho...@gm...>]

Platform: Windows XP, java 1.5.0.15,   1.3.0dev, rev8564, default Xalan 
config

I have a XQuery that generates HTML page using XSLT transformation. From 
time to time and especially when I execute the XQuery for a first time after 
eXist restart, I receive the following screen with title "XQueryServlet 
Error":
Error found
Message: Error
null

Some times there is an entry in the log file:
[P1-7] ERROR (XQueryServlet.java [process]:384) - 
java.lang.NullPointerException

When I execute the XQuery again, there is 30% chance for the same error and 
after the third try, almost always the XQuery works fine until the next 
restart.

I guess there is something the XSLT processor can't find during the first 
execution, that is cached at the time of second execution, but the detailed 
error information, for some reason is not displayed.

Regards,
Thomas