I hear a strange, almost slipping sound sometimes when I take off, or turn a corner, almost like I'm not getting traction. It doesn't happen all the time and never when I take it in..is this normal or sometime I should worry about?

- Weatherford, TX, USA

I own a 2007 Toyota Tundra - 4X4. Several times I noticed that it had moved from where I parked it. It had moved from the spot that I had placed it and rolled backwards, down a fairly steep grade, a distance of around 20 feet. I tried several times to replicate the incident and discovered the following: When parked on a hill without the parking brake engaged the transmission would not "lock" in park while the truck was in 2 wheel drive. This condition can be replicated only when the truck is placed into park immediately after having the anti skid (traction control) respond to a slippery condition. The problem does not occur when the truck is placed into 4 wheel drive. The problem also does not occur if the automated anti skid response does not activate itself. The rolling does not always begin immediately. I have not yet tried to get the same responses while backing the truck up the hill in reverse. I reported this to the local Toyota dealer in Warren, Ohio on Tuesday, December 22, 2009. I am very concerned that this condition may cause serious injury or death to anyone who may find themselves behind the vehicle when it begins to roll.

- Canfield, OH, USA