Java is generally the root of all evil for problems in some way or another! lol Seriously, java is the reknown internet design medium but it does have its problems. I should hope you're using at least Java 1.5

BTW why not try try adding the external drives in part. Not from the root level & not from the main folders. Add them from the sub-folders within so you're adding them bit by bit. It may take a while but it seems it may be overwhelming LW as it is. Start with one of the smaller content folders. If that adds ok, then add more folders. This may even mean you need to separate some of the files into sub-folders if you have too many files in each folder. Start with adding a folder with just a small no. then work your way up.