So, my pump started alarming last night with multiple Critical Failure Codes so had to disconnect and go back onto MDI. This morning, on closer inspection it appears there is a huge hairline crack which starts at the bottom of the rim of the battery cap and goes pretty much the full length down of the battery compartment!!! I haven't dropped the pump so I'm not sure how this has happened and it's very worrying!! I certainly don't use any undue pressure or force when I change the battery and always use my clip to open/close it. It's almost exactly 6 months to the day that I got it and it's always tucked away clipped to middle of my bra or in a Hid-In pouch when I'm in bed.