You're the second person I've seen post with a problem with the installer so I decided to try the installer for myself even though I already had 1.7 installed. Unfortunately, aside from a window resize problem, the installer worked perfectly for me. :-) I'm using RedHat 7.1 and the Java SDK 1.3.1.

Your problem sounds similiar to the one posted in the 'LW 1.7 installation on Mandrake 8.0' thread. I suggested an alternative installation method in that thread that may work for you as well. Have a read. :-)