Cached Credentials Problem

I encountered a strage problem with notebook Vista ultimate SP1 Asus
Lamborgini with fingerprints reader. I join to an active directory domain but
when working with cached credentials outside lan the notebook reboot itself
for 3 time before the desktop. The problem seems bound to security software
installed (Asus security protect manager) that stored encrypted password for
internet site and also windows logon with fingerprint authentication.
Only whe complete uninstall the logon problem disappears.
I repeat that the logon failed is only outside lan when using local cached
credentials, when attached to lan no problems.
I fount another topic with this problem :
Unable to logon - very interesting problem..
Thanks
Michele