I'm having trouble with SQL Server unattended install, what could be wrong?

A. Check install.txt for generic install problems. Then check here for unattended specific stuff.

1. Check MS's article on how to amend the unattended install files at :-
http://support.microsoft.com/support/kb/articles/Q233/3/12.ASP

2. If you get an error "Configure SQLServer Agent / The server service is not started" installing MSDE on NT with the standard unattend.iss response file. Change AutoStart from 61455 to 255 in the unattend.iss file.