CentOS - Jan 2013 - autofs update brakes nested automount

On my CentOS5 boxes the automounter fails after the last update to 
autofs.x86_64 1:5.0.1-0.rc2.177.el5
No update is seen on CentOS6 and things still work there.

The home directory of users is setup using an auto.home map which is 
distributed using NIS:

*    fsutrecht02:/export/home/& /nobackup -noacl 
nasutrecht01:/nobackup/&    /snapshot -ro fazant:/home_backup/

This maps a users home directory and and two subfolders ~/nobackup and 
~/snapshot

Now I see this in my logs:

automount[6510]: parse_mount: parse(sun): can't find multi root thba

I found that this still works:
*    fsutrecht02:/export/home/&

The nested folders do no longer work. If the wildcard is removed, works:

thba    fsutrecht02:/export/home/& /nobackup -noacl 
nasutrecht01:/nobackup/&    /snapshot -ro fazant:/home_backup/

Any idea how wildcards can be made to work (again) with nested mounts? 
Is it a bug?

Thanks,
Theo