I had the same problem with my shifter always popping out of 4th and reverse. I played around with the boot many times and in the end got tired of trying to drive with one hand on the shifter and the other on the wheel. Lets be honest..these things take two hands to control.
I just ordered and installed the Lokar 70-HRB leather shifter boot. I used the original ring from the rubber boot. It fit perfectly and matches the e-brake boot well.