I have tried the suggested fix of deleting the preferences folder. This still did not correct my problem. I had ultrapeer disabled already so I tried enabling it. Still - no LIT files show up. It's almost like that file type is being blocked somehow. I am now receiving very few PDF results but no LIT files at all. Is there possibly a universal block on these types of files?

Thank you for your helpful suggestions, I'll keep trying until we resolve this.