Hm. I'd considered that possibility previously; searches I've done suggested that a look at the NIC card and the general networking setup could be necessary also. Would these be what you're recommending? Looking at the network setup, it seems we have... Maybe six different routers here to provide the connections to the 9 machines in the office. That seems like it could be quite problematic, potentially, but my networking knowledge is rather poor overall. Thank you for the suggestion, though; it reinforces my idea on what the root cause might be.