Network credentials suddenly stop remembering me

Hi,

I been using Vista (bussines edition) from a year ago and I'm enchanted with
it, I work at home connected to a Windows Server 2003 domain, the first time
I get connected I typed my user name and password and checked the "remember"
option, so never get asked again for my credentials. Suddenly the last week
it looks that all my saved passwords were lost, now each time I want to
connect to a shared resource I'm been asked for user name and password,
despite I check the remember me option, it still asking me the credentials
always.

Any idea? everything else is working properly. I have Live OneCare installed
from a year ago too, nothing changed on my server (I'm the domain
administrator so I'm sure nothing happened on the server).

Thanks in advance, any help will be welcome.