Is GNU Java ready?

Hi,

I have just updated my Ubuntu system, which includes GNU Java (for

OpenOffice.org2). Unfortunately, my FOP script complains about

the "png" factory when using the GNU Java.

Therefore, I have "update-alternatives" the system so that it returns

Sun Java as the "java" default.

Question: Has anyone successfully tried GNU Java for the fop?

thank you!
-- 
EL6: Euis Luhuanam