DaveBMW, I'd pull that switch out and clean it. zero dollars, 2 hours max. There are 3 terminals that control various electrical functions. Mine has been flawless for a couple of days now.

good luck and don't let them put it to you.

DavidClass, I'm thinking about trying it.

It's been good since Sunday, so about 30+ starts with no issues.

One odd item is at random times the last row on the dash lights, errors will pop up like "Check brake lights" and others. Then they go away.

It appears that the issue with starting is related to one key and not the other. Just tested it today and the one key will activate all lights and turn the ignition but when attempting to start the x5, nothing. Put the other key and she starts up like nobodies business.

So, do I need a new key or can something be done to this one?

You just went beyond my knowledge. For some reason, some idiot lost one of the keys to my car before I bought it. So I have one and the plastic valet key which is in my remote starter override. Going to have BMW cut me a new one someday..