I have been carrying my M&P .45 for the last couple of weeks. I have the model with the side safety. About 2-3 times a day I find that the safety is not on having moved into the off position all by itself. While this really doesn't affect my "safety" as proper gun handling  negates the issue- I wouldn't have bought one with the safety if I had a choice (Got this one used for $325 so, who is going to bitch?) but it's a bit disconcerting.

Suggestions on how to deal with it? I recently sent one gun back to SW for work and it was an excellent experience, full freight paid both ways, 10 day turnaround etc....

I'm carrying in a Kramer open top scabbard and the safety is being wiped off by my body.....if it were "more positive" this would not be an issue.....

Got pictures of this 'scabbard' youre carrying it in?  EDIT: Googled it.  Looks like its wide open on your body side.  Never carried in a holster like that IWB.

I find my thumb safety on my M&P9c to be very positive.  You know for sure if its engaged or not.  Sounds like you just want it to be a little more heavy.  Harder to engage or disengage.

I carry in a CompTac Minotaur and have yet to have my safety flicked off for any reason.  Full coverage of the firearm ensures the gun will never rub on my skin (which also helps keep rust/corrosion away).

It does not have a "body ear" on it, so the gun is in direct contact with your body...... It looks like this––

http://www.kramerleather.com/productDetail.cfm?productID=10&categoryID=24

It's a great piece of leather, I have one for my 1911's and don't find it to be an issue with them. The M&P is not as positive... What I may end up doing is just removing the safety and putting the plugs in the frame. I didn't really want one with a safety anyway.