samba - Dec 2007 - ExcludeProfileDirs and broken roaming profiles

Hi,

since rolling out roaming profiles, some user profiles are growing very
fast. I like to keep the profiles small and think about changing
ExcludeProfileDirs default settings in Software\Microsoft\Windows NT
\CurrentVersion\Winlogon by System Policies to remove caches, cookies,
recent and other "useless" stuff. 

Which paths could be excluded without "killing" the benefits of
roaming
profiles? Could your send me your settings and/or a working .adm? 

A second problem which comes up one or two times a day - and doesn't
depend on the size of the profiles - are broken profiles at the _first_
login. In most cases Thunderbird and Firefox paths couldn't be loaded
and the user is droped to the "Default User" profile. At a second
login
everything works fine and the profile could be loaded without problems.

Thanks,
Marcus

system information:
samba            3.0.24-6etch9
samba-common     3.0.24-6etch9

[profile$]
        comment = Network Profiles Service
        path = /vol/profiles
        read only = no
        create mask=0600
        directory mask=0770
        hide files = /desktop.ini/Desktop.ini/ntuser.ini/NTUSER.*/

Debian etch: 
Linux 2.6.18-5-686 #1 SMP Wed Oct 3 00:12:50 UTC 2007 i686 GNU/Linux

client side:
100% WinXP SP2, F-Secure 7.10