I'm a client support technician at a hospital with 3000+ PC's, 90+ % of them being Windows XP... the other techs and I have had this problem for months now where random computers will lose the default printer checkmark (no printer has the checkmark) and users cannot set a default printer nor print, unless the techs reset the print spooler service or re-install a printer (which in effect resets the print spooler service anyway). This seems to be independent of hardware or specific software or whether or not it is an autologin profile. Several of us have spent hours on Google trying to find anyone who has a similar situation, but to no avail... the closest we have come is to seeing that it is possible that, if the profile is sufficiently large, the profile is still loading when the print spooler tries to start but, since the profile is still loading, the service never starts... we have looked at a couple machines that this has happened on and the profile in question was indeed large (>500MB), but I have just seen the same issue on a machine where the associated profile was relatively small (<80MB). We know it is not a computer-specific issue because given one PC, one user will have the problem, but another user logs in and the problem isn't there.
Out of 4000 or so PCs, this has only happened on about 25-30 in our environment...
Any thoughts?