new key won't start my car!

[Swan]

sorry if this has been covered . . . i did a hasty search and couldn't find any threads covering my problem. so, i rely on the kind support of my fellow benzers. i ordered a new key from the dealer (local key shops wanted double or more to duplicate my current key). it works okay in both doors, the glovebox and the trunk, but not at all in the ignition. i noticed the old key has sort of rounded edges from years of use. should i take my dremel tool and grind the corners off a little so it looks more like the old key?

[neanderthal]

get the dealer to make you a new one.

if the ignition hasnt been changed and one key operates all the locks, your key should work everywhere.

[danwatt]

Or your ignition lock cylinder has worn to some wierd point where only the old key will work. Chances are slim, but you never know. Bring it to the dealer and demonstrate it. If another key doesn't work, check the lock cylinder.