What do you mean by nothing displays but the white box? Did the password reset utility go through the motions and just not work?
If thats the case, you have two options really:
1: Do a whole pile of fancycommand line trickery in single user mode (I can't tell you much more than how to get into single user mode - boot holding apple-S). I guess if you can google how to create a new user from terminal, you might be able to log in as that user. But you will need asmin privileges to get at the data in the other account, or to changes its passwords. That will rely on the Mac recognising your root password. While this is probably the same as your account password, it may be stored separately, so might not have been corrupted.
2: Boot into firewire target mode, rescue your data with another Mac, then do an erase and install.
Or you could take it to a service provider. But then you will have to pay of course.
I guess you could try repairing the disk permissions from disk utility. This is also on your install disc 1. Try the password reset afterwards again.