With Java VM 1.6.0_01-ea-b01 we have the follow regressions. The problem occur not with the final 1.6.
 
A JTextField does not receive the focus and it is impossible to enter text in it.
The problem occur only with an applet. In a standalone application it work. To reproduce the problem I have attached a sample. With a double click on the index.html you can see it in a browser. In the large text filed you can't enter text with the 1.6.0_01-ea-b01. We have test it with Firefox 2.001 and IE 7.0 on Windows.