I have an old R4 myself for a few weeks. My friends also wanted one, so I went to the same online store and ordered two new ones. Well, I got it today, and to my surprise, it was a new SDHC-support version. I put it in my DS to see if it would work and I immediatly saw "Loading...", without even having inserted the MicroSD card (regular 2GB). I then also plugged in the SD card and again, "Loading...". I tried my own R4 with an SD and got the message that the "SD/TF card couldn't be found". I tried my own SD card (which works fine on my R4) in the SDHC-version, but it still kept on "Loading...". Then I tried the SECOND R4 SDHC, with the same problems! Do you HAVE to use an SDHC card or something? Or are both my SDHC-cards just broken?