Status changed from (1) Pending to (5) Completed

I checked all of these computers again today.  Two
were working today and one different behavior.

Note: This problem morphs a bit and there are ~3
problems that might be related.  
1) The most wide spread issue is the lack of APSC
101 printer as an entry in the print list.  The
size of the list of available printers changes
from machine to machine.  I've seen as few as 3
entries.  At other times, perhaps 10 or 15 entries.

2) Machine 20050074 has APSC101 in the list, but
when attempting to print:
"The printer has not yet responded. Do you want to
continue to wait for the printer?" 

3) on machine in location I6, simply selecting
APSC101 printer cause the host application to hang.

As of 30 minutes ago the following two systems
were okay:
Location H5 - 20050072
Location J1 - 20050069

With the variable printer list, perhaps many of
these machines intermittently work/don't work.

Status changed from (5) Completed to (1) Pending

Status changed from (1) Pending to (5) Completed

and another...
20050099 - location L1

Adding 2 more computers with this problem:
20050090 - location I6
20040651 - location I4

Also, raising priority because fear this problem
may be spreading and could shut the main lab down
for printing if not resolved soon.

Computers located on last row, closest to printers
- all in a row.

2005074
This computer gets the full list of printer
choices but issues the following message when
attempting to print:
"The printer has not yet responded. Do you want to
continue to wait for the printer?" 

Clicking yes, simple waits and repeats the message.

THe next 3 computers in a row have a possibly
related problem.  (20050059 20050089 20050074)
These systems show only a small partial list of
printer options.  THe list size is as low as 2
(none of which are printers) and the max was 6
items.  Typically, the radar/APSC101 was not
listed.  When APSC101 was listed, it typically led
to the same message noted above.  In in case, the
print succeeded.

I cold booted all of these systems and checked all
systems across the desk (others worked).  I
randomly checked other systems in the lab and
found no more occurrence of the problem.

After 1 hour, the problem still persisted, though
the number of printer options varied.