I have a new Phantom 3 standard and the SD card seems stuck. The new one doesn't easily slide in and trigger the ejection mechanism. Since it is my second device, I'm able to compare the functionality of the SD card slot with the older one, which works perfectly.

Are you using the "stock" SD card that came with the Phantom or did you replace it with something different?

May I know where you bought it?
If there is something wrong with the SD card slot on the aircraft, we do suggest you to contact your dealer or send it in to our service center, we'd like to help you handle it.

Just wondering if the SD card that is stuck, still functions?  

Did you resolve this?

I also cannot get card out of gimbal. It works well but will not come out. Any suggestions?

Odds are you will have to send it in or return it. Mine never jammed, but ive seen many many posts of the ejection mechanism jamming. There is no easy way to get the card out without completely disassembling your camera and voiding your warranty.

I thought mine was too, I pushed it in with a finger nail until I felt a little click then gently pulled it out with tweezers. Eazy Peazy!