Saturday morn. going to work in the midst of a fast 5 inch snow blizzard, my VX handled like a dream, passing big rigs on the expy doin bout 55mph w/out plowed roads. No problem until I reached the off ramp and applied the breaks. I was down to about 25 mph when if felt like my breakes locked. I started to skid( A STRAIGHT SKID ), but by break pedal felt like it stopped at half way. It felt just like when its depressed when the engine is off. Idid feel a great pulsing sensation when pressing down, but still only until I came to FULL STOP did I get control of the breaks again. So there I am just 3 blocks from work on the unplowed main road,doin no more than 20 mph when I was about to turn rt into my driveway,when it happened again. I couldnt even turn into the driveway because the breaks went halfway down , pulsated & caused me to go into a straight skid. In the uncleared parking lot on the snow it kept happening, but when it rained a few hrs later and all turned to ice , I did some hard driving in the empty lot and had no problems breaking . I had it to near 45 mph & hit the breaks hard and it was beautiful, Stopprd on a dime. But when I drove very slow on some patches of snow it all happened again, What can this be?