Antenna is using wtk doing its, jobs, and wtk has its own thinking way.
I had exact the same pre-verification error when we did the similar things like you. Please don't customize the libraries!!!
You may need to reinstall
Java, ant and wtk to undo your mistake. And it might not work either. I don't know why
. I made one j2me programmer's machine work, but not the other. I had to switch a C++/symbian programmer's machine with one of our j2me programmer's machine to have undone that.
Of course, reformat the hard disk will always work!