Network hanging/freezing

I have a situation where a 10.2.8 network (1 server at 10.2.8 Server and 2 clients, both at 10.2.8 Client) hangs periodically when the users who are mounting their home directories over the network are using Excel 10.1.5. I have ensured that each copy of Excel has a different serial number (they have 4 licenses, of which only 2 have been installed since there are only 2 client machines) and that each copy of Excel is locally installed on a client machine. Their Excel data all reside in home directories located on the server and which they access through network mounting of their home directories onto their client machines. Also, they insist on communal home directories for business reasons. When the network freezes, the clients sometimes pop up an error dialog that the server cannot be found or they display a spinning beachball in place of the cursor without any dialog box (nothing is evident on the server--there are no corresponding hangs on the server when this is happening to the clients). The users have found that if they disconnect the RJ45 network cables from the Netgear DS108 10/100 autosensing hub and reconnect them, their problem sometimes fixes itself. In other cases, it requires a reboot of all machines on the network (which is a royal pain). However, once when the network froze but before they disconnected and reconnected the RJ45s, I got one of the more technical users to ping the clients from the server and they got a pretty decent response time (around 0.392ms) so that tells me that it's not the Netgear DS108 hub hanging or blocking the network traffic even though the clients are displaying a spinning beachball in place of the cursor. Also, in the past few times the users have reported that these freezes occur, I've looked at /var/log/system.log and found they have been preceded by an error message from Excel stating: <path to Excel>: *** Warning: ATSUMeasureText has been deprecated. Use ATSUGetUnjustifiedBounds instead. I have sat there for an entire day when only one user is manipulating their Excel data across the network and there have not been any problems. This is driving both the users and I crazy. As such, I have a couple of questions: 1. Is this a known Excel problem? I can't seem to find any mention of it on the Microsoft Excel for Macintosh site. 2. Does Excel constantly write to a temporary or preferences file somewhere and could the fact that they are using communal home directories be causing this? However, the users have 3 communal home directories (owners, managers and staff) with multiple simultaneous login capability and when the network freezes, the two users are not using the same communal home directories (i.e. one is logged in as owners and the other is logged in as staff), so they would be writing to different Library/Preference subdirectories. 3. Is this something to do with the AFP maxout problem? But with only two users on a 100BT network that only use Excel with at most 1,000 line spreadsheets, isn't it a bit ridiculous? If it is to do with the AFP maxout problem, is the AFP maxout problem fixed in Panther Server? 4. Could this be a situation where the client or the autosensing hub is sensing the wrong speed of data coming from the server? i.e. it resets to 10Mbps instead of the default 100Mbps, thus causing the user to lose connection to the server and their client machines to freeze up? This network hang/freeze problem is driving me nuts. Especially when I'm not around when it happens. I see little hints of it in the logs but no direct evidence that points the cause to be anything specific. I have asked the users to quit out of Excel every hour or two (to flush out any possible memory leaks or other problems that Excel may be developing) and I will be installing NetCapture by Neon Software to collect data that can be later analyzed by Neon's NetMinder software. If anyone out there has any other suggestions that I haven't tried, I'd love to hear them. Thanks in advance.