So you bought an R4 for your DS and the microSD adapter doesn't work. You probably don't want to send it back to hong kong. Here's an easy fix.
I decided to make an instructable about 4 months after I made the project, so I took the picture with the r4, adapter and ds from John Bobosh.
His site: Digital Claxon
Step 1: Parts
You will need:
Step 2: Open up the adapter
I couldn't open it by hand, so I used a saw and removed the part, where you insert the microSD. Be careful not to cut off the metal inside. I somehow opened it by pushing and pulling the usb and microSD part.
Step 3: Find the problem
The problem is probably the part, that holds the card in place. Mine just fell off, when I opened it.
Step 4: Repair
Place the metal, that holds the card, over the socket. You will notice that it almost snaps into place.
Now use duct tape to tape the board and the plate together.
Step 5: Use it
You can already use it. You could use more duct tape to protect it.