[andy stewart]

My SD memory card is not recognised by my Samsung Galaxy Ace.

Yet I take the SD card out of my phone and put it in my partners phone (Samsung Galaxy Y) and its fine.

So something is wrong with my phone. The SD card is fine.

Has anybody else experienced this?

[B. Diddy]

Welcome to Android Central! This kind of thing can occur from time to time. Two things to try:

1. Make sure the microSD card is fully seated in your Ace's slot--it usually click into place, but in some devices, you just have to make sure it's pushed all the way in.
2. If that doesn't work, you may have to reformat the card on your computer and try again. You can back up your data onto your computer first.