I have the same problem on my 95 sidekick, and it's not the boot-- I ran it with the boot removed, and it still popped out of 4-low. The shifter doesn't contact the floor cutout, and I've changed the tranny bushings. I pulled the transfer case and took it to a good tranny/transfer case shop, and they haven't found any issues with the case itself. I'm as mystified as kickscrawler91.