That's odd it gets to the loading stage & doesn't get any further. If an OSX update upsets LW it's generally a Java issue. May I suggest you re-install this file
http://www.apple.com/downloads/macos...update142.html
If & only "if" it won't let you then go to the OSX HDD > Library > Receipts folder & remove Java 1.4.2Update file only & trash it. Then try installing again. But don't remove any other file from the receipts folder.
Receipts folder sample image