I have the R4DS and had it working perfectly with a 2gb Kingston micro sd, so I was keen to upgrade to 4gb, but each time I have tried, the ds gets stuck at "Loading..." and gets no further. I have used the same software as on the 2gb, I have tried newer software from the R4DS site, I have formatted the micro sd card with the default settings in Win XP, but still no joy. Will it just not work with 4gb, or this particular 4gb card? According to the info on the card, it is a "Sandisk 4gb micro sd hc". Have I bought an incompatible card or is there anything else I can try please? Any advice is greatly appreciated.