problem with 4wd

alright, i was out playing in the sand around here, got stuck, put it in 4 low and only the rear right tire and the front left tire were spinning (got me more stuck) so i put it in 4 high and they all spun, but wouldnt get me out.....any input into what would cause this? i heard that the front tires need one full rotation for the 4wd to kick in, is that true?

95 jimmy, 4dr, 4x4, vin W, 92k miles


*btw i had to call my friend and he came over with his rock crawler and pulled me out, i was burried to the axles by the time i gave up :P *

Thats normal without posi - wheel with least traction spins due to open differentials. G80 option adds posi to rear - no front option.