No taskbar when logging on

[Jobos]

I've had a number of users complaining that when they logon they are left with a blank desktop and no taskbar at all. The users in question use redirected desktop so it looks like the logon process is hanging partway through. Login off and back on again restores normal operation but this issue is reoccurring every day. The machines are XP with server 2003 and it is affecting random machines and random users.