Again--I clean out the crud on the rollers inside my mouse regularly, so I know it is not caused by that. But my pointer seems to freeze ever other second or so as I move it across my screen and stop there very briefly, and then jerky way ahead to "catchup" from the previous moment of inactivity.
It's Very annoying and hard to put my pointer on anything now without lots of effort.

Does anybody know what I can to to fix that?
(Board Hosts-->I don't know why the word "jerky" didn't show up in my title previously, so I'm posting this again(If the system can't handle quotation marks, I wish I would have been promted, and not take up extra space on the board)

I've come across this problem before and it is not caused by a dirty mouse (though that's the answer you'd give on your A+ certification exam). It is caused by some sort of inscrutible software glitch. In one case, the problem simply went away. In another, I got rid of it by restoring an earlier version of the registry (by booting to a command prompt and typing "scanreg /restore" (without quotes and with space between g and /). You're right, it is probably the most annoying bug I've ever encountered. A mouse pointer with epilepsy.

I would first try a different mouse and see if you have the same problem. If so, you might remove the mouse drivers in Device Manager, reboot, and let Windows reinstall them.

Just as a footnote, in both of my cases it wasn't only the mouse pointer that was jerky but also the cursor in any text program like Word. You'd see the spasmodic movement of the cursor by holding down the space bar. (In this case, removing and reinstalling the mouse drivers won't help.)

Yes, although my incredably slow one finger typing "skills" don't notice any keyboard irradic behavior(HaHa-I'm at work now and will hold down a key on my keyboard when I get home to see if it is affected too)--But,I do also notice the little IE world(in the upper right corner of my browser screen)turning in a "jerky fashion" instead of smoothly as before. And my browser stops and "thinks" at about the same time as the "mouse jerk".

Does that indicate anything?

Have you been into Mouse properties in Control Panel and twiddled with the settings there ?

Or else, maybe an IRQ conflict with another piece of hardware ?

No twiddling has happened in the Mouse Properties of Control Panel. How do I solve an IRQ conflict? (and what is that?)

What I meant was for you to go and twiddle !!
Check the Motion tab in Mouse icon and see if anything changes when you move the slider for Pointer Speed.

Re IRQs
Go to Device Manager and double click Computer at the top of the list.
Look at Interrupt Requests and see what number IRQ your mouse is using - then see if another device is using the same number IRQ.

Ok, I'll "twiddle"(Ha),
What do you think the simultanious(exact same time as my curser "halt") jerky action of my browser indicates?

I guess IRQ means "interruption request"? If it does, I DEFINITELY will check that for a clue--because things ARE definitely going thru "intermitant epileptic jerky spasms" or interruptions.

Well, I was thinking maybe an IRQ conflict between mouse and modem.

It indicates to me it isn't specifically a problem with your mouse, which was my experience in the two cases I mentioned. It was the mouse, the cursor, etc. It was a more general problem with the software environment.

I didn't mention it because I didn't think it was related, but I've also noticed my clock losing a few minutes a day(15 mins? in 18 hrs), but corrects itself again after a reboot.

Does that sound like related to the same issue?

Inside of the mouse are two bars that you clean. There is also a wheel. I clean that too but I had a mouse that apparently had a displaced spring in the wheel. I could feel it catching before the pointer would shoot to catch up.

Of course this had no effect on IE.

It does not sound like the same issue to me, but losing a few minutes off your clock everyday is a very good sign that your CMOS battery is dying. It's a little button type battery located on your motherboard and should be easily replaceable (let's hope or you are SOL). When it dies completely, you will lose any custom settings and will have to reconfigure them every time you boot.

From past experience trying to make old slow puters do new fast things, it was ALWAYS some background/other programs than the one at hand, trying for a turn at the processor and memory routing, etc. WIn9X is supposed to be above that behavior , but can stall out when process priorities are not handled properly.
HOW many things are you trying to get windows to do at the same time? Downloading files while running music players and surfing graphic intensive sites is a good way too get the mouse and little planet in the corner jerking like crazy.

From a totally different angle, mouse cords do ware out, a broken wire inside the insulation can be sorta held in contact by friction and position, but by the same things changinging with mouse movement, you get make and break info from mouse to screen.

Another angle ?
IE exploder can be partially corrupted and still have most functions, just not doing them too well. Have you tried running IE repair tool? IT's amazing what gets fixed by some thing that seems not to be at issue.
Find it easy by running MSINFO32, drop the tools menu down and choose IE repair.