Hi guys, I'm getting a little frustrated trying to upload some photos right now. I've got Macbook version 10.5.8 and I am using a Sony multi-card reader to upload photos since I do not have the camera's usb handy. Previously I have had no trouble uploading photos from my 2gb SD card, but now that I am attempting this with a 4gb memory card the device is not even registering on the computer. I'm having a hard time believing that it is a problem with the card size, because wouldn't the device at least appear as being active regardless o the size? I have tried it in both usb ports which are both functional and the green light comes on indicating that it is receiving power. Anyway, I'm stumped so any help that anyone can provide would be much appreciated. Thanks.