BTW, now I remember that I fixed some issue in 5.1 which was that resetpwd.awk tried to use "rpm" which was not present on some Ubuntu. Maybe it's your case. If that's the case, installing "rpm" and re-capturing the template should solve the issue. Or you can even try to grab VCD 5.1 scripts and use them - I believe they're backwards compatible. But this is of course on your own risk 
Another thing I can think of is special characters. Auto-generated passwords may include
!$#%
Have you tried with manual passwords having only letters?
/Andrii