I dropped my razr hd and it landed on the bottom right side (looking at the screen). Ever since that my phone either wants me to format the card since its corrupted or just doesn't recognize it's their. It happens randomly when i'm listening to music or using the internet and i just get a notification in the top bar saying to format it. When i remove it and put it back in it works for awhile. I tried it in another phone and no problems. None of the data is corrupted though. I haven't tried another sd card in the phone since i have none.
You should try and get your hands on another SD card. If the one you currently have is working in other devices, it would indicate something is wrong with the device itself. Though this can't be verified without testing a different memory card first.
What you are describing sounds a lot more like a software issue than a hardware fault, though, so why it started occurring only after you dropped your phone is a mystery to me.
Have you tried doing a factory reset to restore it to factory condition? It may be a software issue after all, and coincidentally started at the same time as you dropped the phone.