This does not happen 100% of the time, but I have isolated the effect to keyclone.
Playing two instances of wow. One Blizzard account, two lics for wow.
After playing for 5-10 minutes, I get a delay on releasing keys. So if I am running with W, and I let go of W, it will continue to run for a second. While it is doing this, if I am steering with holding the right mouse button, it gets very chunky.
Only difference on my end is standard windows updates and properly clocked my ran. I didn't realize it was running at 2133, and sped it up to 3600. I went back on set it to default and tested again with same results.
I have test WoW dual box without keyclone. Just got one character on follow and played the other one in an area killing things and running around as I would if I was dual boxing as normal, and I did not have any issues.
I downloaded keyclone again from the site, ran in the fresh program, and still experienced the same issue.
Any suggestions would help, thank you.