acad 13; commands mysteriously cancel, start into new command

So I just installed a new version of 13 and got it set up with my keystrokes and toolbars and all that the way I like it and I'm having a recurring problem. I quickly type keystrokes and use right click to enter the command. The command will start as I can see in the command line but then it will change into some totally unrelated command. For example, I type "ex" for extend and I right click. I see in the command line acad initiates "extend" but then (without me entering another keystroke) cancels it and enters something like "_camera" or something else totally unrelated.

I have noticed that if I enter commands slowly and deliberately this does not happen. But I'm not just being sloppy because I go back to acad 2009 and work the same (quick) way and have no problems. I have also tried other people's 2013 in our office and I have the same problem on their machines. (BTW, they do not seem to be bothered by this but I can't work with it.)

-yes, the new command that appears usually starts with _ (underscore).

-yes, this most often happens with the "ex" command, but it does happen with others too.

Has anyone else come across this issue? Can I be the only one??? Any help is greatly appreciated. Also, this is my first post but I have found answers to many of my autocad questions here before so thank you to all contributors.

Try setting the Autocomplete option to OFF and see if it makes any difference.

Check your right click settings.

Autocomplete is off and I have my right click settings to repeat last commands in default and edit modes.

It seems like it just can't handle the commands typed and entered too quickly. I tried checking the "enable hardware acceleration" under 3dconfig to try to speed things up but I still have this problem. It really seems to me like a bug in 2013. Hopefully not though and there is something that will make things run smoother.

Issue seems to be with the dynamic input feature. Once all settings in that were off I no longer experienced the delay with inputting commands.

Also, the issue with a command canceling and mysteriously turning into a new, unrelated command was a problem with "pickdrag". That had to be set to 0 and that stopped happening.

My takeaway from all this- autocad is trying to be a little too whizbang and it's making things glitchy and problematic...at least for my basic needs.