When I'm in the "barter" screen, and click on the "+" or "-" add/reduce gold controls, sometimes I can hold down the mouse button and get it to increment automatically, other times I have to click for every single increment. It can happen with the same vendor in the same buy/sell session, or in different sessions. A few times I've had it work correctly for a period of time, but that hasn't happened in quite a while. Sometimes it will work the first time I try it, then as soon as I stop holding the mouse button, it stops working. Other times it doesn't work initially, then all of a sudden works until I let up the mouse button, and I'm back to countless clicks. Most of the time it simply won't work at all.

When it's a low value item it's not really a big deal. But, when it's a high value item & I'm trying to change the gold amount by dozens or hundreds, well, I usually just give up because it's just not worth the effort (not to mention a sure way to get carpal tunnel syndrome). This is really, really annoying ... is there any way to fix this so that if I hold down the mouse button it always increments automatically? Or am I missing something? FYI, I'm using the GOTY edition.

If on PC, the http://planetelderscrolls.gamespy.com/View.php?view=utilities.detail&id=22 has the option to "Improve barter sum increase/decrease speed" which works very well.

If on Xbox, pressing the Right or Left trigger will sometimes speed up the digits.

I'm using the PC version, and just tried the FPS Optimizer fix but that did not improve things any. Any other suggestions?

It works perfect for me.
Are you sure you're using the FPS O correctly?

Well, as to whether I'm using it correctly, that I can't say for sure, but as far as I can tell, it's working correctly. As you can probably tell, I am very new to Morrowind.

I set up FPS (& Morrowind) per the directions at the Morrowind Expanded page (http://morrowind2009.wordpress.com/), and I start FPS before starting Morrowind. I did have to switch to "novice mode" to find the "Improve barter sum increase/decrease speed" option, but other than that, I'm not sure what the correct settings should be. For what it's worth, I'm also running MGE.

Open your morrowind.ini and find the line Max FPS=. Change the default value (I think it's 240) to whatever your monitor's refresh rate, usually 60, 75 or 80.

It is to do with the area there is to click on the buttons - reduce the refresh rate and the area becomes more available.

Just tried that, and I can't see any difference in the way the controls act, unfortunately.

Well, I have no idea why the FPS Optimizer options don't work for you, because they work for me just fine.
But another option is to use the MGE macros.
You can set up Macros for + and - 100 or 1000 in the Barter screen.