Your issue is going to be simple security. What user is logged in to each machine? Do you have the same username and passwords on each machine? Can you access the printers on the xp machine from each by typing in:
You should get a list of shared printers. If this shows and you still can not print. Security needs to be modified on the printer object.
Also note that Vista machines by default are in WORKGROUP, XP home used MSHOME so if you have not customized that i would make this change, To do this follow these steps:
To find out the existing workgroup name for a computer running Windows XP, do the following:
1.Click Start, right-click My Computer, and then click Properties.
2. In the System Properties dialog box, click the Computer Name tab and note the name of the workgroup
To do this on Vista:
To configure the workgroup name for a computer running Windows Vista:
1. In the Computer name, domain, and workgroup settings section of the System window, click Change settings.
2. On the Computer Name tab of the System Properties dialog box, click Change.
3. In the Computer Name/Domain Changes dialog box, type the name of the workgroup being used by the other computers on your network in Workgroup, and then click OK. Figure 3 shows an example.
4. When you are prompted with a welcome message box, click OK. When prompted with a message box to restart your computer, click OK.
5. Click Close. When prompted to restart the computer, click Restart Now.
Norton may be an issue but just temporarily disable it to see if you can then print. If that is the case then there will be windows sharing options or netbios option within Norton.
More information can be found on TechNet.
Please if this does not help come back and give us some more specifics!