The "computer adjustment" may have been to whitelist QB. To tell your browser program that it is OK to let QB run scripts because the QB reply box always uses a script even though other boards running similar board software do not. It is not an adjustment at the level of the computer hardware.
[Side trip #1. You can skip this.]
The type of computer and operating system is like saying what kind of machine your machine is. (Is it an Apple running OS X? Is it a longarm instead of a regular sized sewing machine?)
The type of browser program is like saying what brand of machine your machine is. (Do you use Firefox version 35? Is your regular sized sewing machine a Brother SE400?)
The type of browser add-on is like saying what kind of foot you have on your machine. (Are you running NoScript? Are you using the buttonhole foot?)
[End of side trip #1.]
[Side trip #2.]
My problem was I was unable to input a line break. When I hit Enter nothing happened. I have some run-on posts from before I figured out this problem. And another problem was stranger. I type with a modified keyboard. The physical keyboard has the wrong symbols on it so I use software controls (at the level of the operating system) to get the "virtual keyboard" I want. Sometimes the cats step on the keyboard and turn the virtual keyboard off. And when that happened the reply box would not always update to the current keyboard even when I reloaded the page.
[End side trip #2.]
I run the browser Firefox 35.0 with the add-on NoScript 2.6 which stops sites from auto-playing scripts written with Flash and other annoying things that make my computer use extra thinking time. I keep most sites "blacklisted", meaning no, I do not let them run their scripts. No I do not want your news video to auto play when I go to its page. No, I NEVER want to hear the music you have in the background of your sewing shop. I have to go to NoScript's control panel and tell it to "whitelist" or say Yes to a site. It will let me allow it temporarily (until I shut down Firefox or revoke all temporary permissions) or allow it permanently.
Once I said Yes to letting QB run scripts, the reply box problems went away.
So why am I bothering to post a totally different set of problems?
Because when NoScript is blocking a script that really WANTS to run, the script slows down EVERYTHING in the browser program. Including typing input.
Pressing the A/a button may be sending the script a signal to stop running and stop using up all the computer's thinking power.