I have been able to play this game pretty much without problems except now when Karla comes to the bank to interview Lucas. I cannot get past this sequence. I answer all the questions and win all the action sequences but no matter what, Lucas ends up distraught and gets put in the insane asylum.

Have you checked out the walkthrough HERE. I haven't played the game myself. Hope it will help.

This sounds like a case of not doing something ahead of time rather than a bug. Check the walkthrough Cathy linked to. ***UHS Hints*** might also be of use. If you can't figure out what you may have missed, ask for a Hint and we'll try to help out. It's been years since I played this game though.