Sounds like when your ear pops, the pressure then becomes unequal in your ear. When that happens, it affects your balance as your inner ear is where the mechanism for balance lies, and it will make you dizzy (I have done this to myself before when I had a cold and blew my nose really hard). So the question then is, what exactly are you doing that is making it pop and making the pressure uneven?
Are you holding your breath while doing the exercises? You may be doing this and not even realize it.