Shared Printer in Windows XP Sp2 getting disconnected frequently

Hi, In our organization we had all the computers with pre-loaded Windows XP
Sp2 operating System. There is a local printer in computer1 and shared the
same printer to computer2 and computer3. Printer is printing perfectly. But
after 1 or 2 minutes of idle time it is getting disconnected in the shared
computers(computer2 and computer3).

I end up with trying permissions giving fully to all the computers for the
SHARED PRINTER. But no result for me.

Provide me an early solution.

Thanks in advance................