The cruise control on my 1999 CLK430 will not stay "engaged" at speeds in excess of approximately 72mph. It will momentarily engage, but it seems that as soon as the computer detects a need to increase/decrease throttle input, it disengages. I have no problems at lower speeds. I'm quite sure this is a "new" problem for my car (i.e. it used to work).

Has anyone experienced/resolved this problem?