For the last couple of years I've used a MacPro + SnowLeopard at work. We have a Windows network so I have to do a network login into our domain. I sometimes login with my local Mac machine account too.
The login process (for non-local accounts) has always been slow - after an initial boot, clicking on the login box to cycle through the information usually reveals a red dot and the words 'no network accounts available' for a minute or s before the dot goes green and it tells me they are available. Recently however it has taken a turn for the worse - trying to login to an existing session, eg on returning to work in the morning, machine left on overnight, it is impossible to login at all. After entering credentials the 'busy' spinner spins and will do so all day and a reboot is required. The issue never appears on the first login after a reboot. What can I do do fix it?