This has been confirmed multiple times on the users mailing list.
The only current workaraound is to downgrade the Java version to _u21 or _u22, both of which are unfortunately known to contain serious security issues.
There is a thread on the user mailing list which indicates how to have several versions of the Java environment installed on a Ubuntu machine and then be able to choose which version one wants to run with LibreOffice.
As the problem appears to lie with the JDK version and not LibreOffice as such, and there is a workaround, I'm setting this issue to resolved "not our bug".
This has been confirmed multiple times on the users mailing list.
The only current workaraound is to downgrade the Java version to _u21 or _u22, both of which are unfortunately known to contain serious security issues.
There is a thread on the user mailing list which indicates how to have several versions of the Java environment installed on a Ubuntu machine and then be able to choose which version one wants to run with LibreOffice.
As the problem appears to lie with the JDK version and not LibreOffice as such, and there is a workaround, I'm setting this issue to resolved "not our bug".
Alex