I have a number of users who randomly get these error messages that say
something like there is a notification service error regarding [printer
name] from [server they are connected to](error code 2). They are not
directly doing anything with the printer when these happen (for example,
my manager got about 20 of them yesterday while he was out at meetings).
I have even received them from printers that I am not connected to at all.

Any suggestions?