Curious double charaters while typing

Question

As soon as my iMac loaded and I began looking at all the cool stuff, I started to send Mail (eMail) and noticed a strange problem as I typed. Foor some reason, I experience random double character strikes like the one at the beginning of this sentence. At first I thought it might be a preference setting gone wild, but after dialing the setting upp to a faster repeat rate or down for the slower one, there doesn''t seem to be a difference. Sometime punctuation is affected too. Do I have a bad keyboard? Is the keyboard software confused perhaps, or is this a ham-fisted user problem? FYI- this post is mild compared to email text I type -- which is usually full of double strikes. This happens everywhere i.e. it involves all uses of thee keybooard in all applications.. In my 17+ years of using a Mac, I've never seen this one before.
Does this look familiar to anybody?
iMac   Mac OS X (10.4.9)  

Answer 1

"I've beeen having this exaact same problem. Did any of the suggestions here work for you?"
After I moved, I also had the exact same problem, and discovered it had to do with the new location of my computer. Since I simultaneously began to have sharp pains in both wrists, I simply could not tolerate the situation for any length of time at all, and continually made changes until I discovered the solution - at least for me.
http://www.apple.com/about/ergonomics/index.html
Search "ergonomics" in Support, or google "typing ergonomics" for more information on how to properly position oneself for better productivity and less risk of pain and/or injury when using a typewriter or computer keyboard.
I originally was sitting at a chair seat height that was more than 12" below the height at which the keyboard sat. As long as I sit no more than 9" below the height at which the keyboard sits, I have no typing accuracy problem, and no wrist pain. Measurements are taken while seated, so as to include any compression of the chair seat height.
When I now return myself to that original faulty height configuration, my typing once again makes it look like I'm just learning to spell. I originally got myself into that bad situation by quickly setting up my computer at the first empty desk, rather than first giving any thought to the positioning.
Unfortunately, those measurements are only what works for me, based on my height/arm length/keyboard height/seat height. Each person using a keyboard needs to properly fit themselves into their individual best position. Since correcting desktop height can be nearly impossible, it might be easier to set the keyboard at a different level than the display, or use a different chair.