Of course, this might not be of any help whatsoever, have you tried to run this command:

clear

I know whenever I was experimenting with building a Linux OS from source code (never do this; Bad Brandon, bad!), I ran into a similar error that didn't necessarily have to do with the escape key, per say, but my console would bring up garbage like this sometimes. You could also try hitting Ctrl-C a few times when this occurs or if that doesn't work, logout and then log back in and you should be good to go.

You can always disable completion, but thats not funny.

Did you Google: "Display all * possibilities? (y or n)" you will find some info about this.

Check this out:
http://superuser.com/questions/37148/how-to-disable-double-tab-to-show-available-commands-in-linux-console

Maybe you can just disable completion with the ESC key or completion on empty strings. I will see if I can find anything.