I was going to report that I found the problem. It was that one of my laptops was hot and the thermostat kicked in so it was slowed down. But that's been resolved.
However, I have a new problem that I've never seen before. One of my computers had all instances of WoW crash at the same time. I've never seen that ever before. Either the video card crashes and resets or the entire computer would crash, but never all of the wow clients.
Update on using 7 computers with over 40 accounts:
I've disabled SLI on all of my computers in an attempt to try to resolve the computer crashes. I went to Stormwind with 43 characters on 7 computers and none of the computers crashed. I got the same performance on my machines that I got when SLI was enabled. That surprised me and I learned searching forums on the Internet that although WoW will work with SLI, it gives very little if any performance gain. I also disabled the screen FPS (frames per second) update through the ISBoxer setting. I went for about 6 hours with heavy PvP combat against about 200 opponents at prime time in the afternoon on Saturday as a test to see if the computer crash was fixed. At about the 5 hour mark, one of the computers crashed. That was a LOT longer than what it had been doing before. Before, I would get a crash or two for every AV game I played. The interesting thing I noticed just before the computer crashed was that I saw ISBoxer reload all of the characters on all machines. It appears that the updating to the screens made by ISBoxer may be related to the computer crashes, but I'm not sure because I turned off SLI at the same time I disabled screen updates for FPS. I've turned off all settings for any keys other than Repeater for mouse and keys to all of the clients. I'm unsure why ISBoxer reloaded all of the characters, I don't have any keys mapped to do that. Is there a specific set of keystrokes that will cause ISBoxer to reload characters? I know that if I go to the InnerSpace icon and select to start the Character Set, it will reload them, but I didn't do that. I had done that occasionally in the past when one client crashed to get it restarted.
There are a lot of advantages to using ISBoxer and InputDirector over Octopus. Not just support-wise, but also technical advantages. The main one being the mouse cursors in all windows are very smooth and allow selection of many things at the same time. With Octopus, the characters would turn downward on a lot of clients and had to be re-positioned often.
I've been using the repeater default with a blacklist of keys instead of Key Maps. If Key Maps is a better way to use ISBoxer, I may reconfigure to use that, but it seemed a lot easier to enable keyboard repeat and mouse repeat using the repeater.