Given it is happening to more than one machine AND it started just after you changed SYmantec products I suspect it is the culprit and your best bet would be to cont them.
In your first post you only mentioned one machine so I was focused on it, but since it is spreading. I would try removing Norton from a machine (just to check) you you can have more certainty when you contact Symantec.
BSOD'S are always a combination of things but in over 40,000 BSOD analysis IMHO Norton products are rubbish. It may simply be norton on Dell does work norton on HP doesnt. We would need much more information.