Samsung :: Moment Won't Connect With Usb / Won't Let Me Mount SD Card

I had to get my moment replace because the screen screwed up. I had Easyteher on my phone prior to getting this one and worked good, it was working when first I hooked this phone up, it let me mount it to my computer and easytether worked fine. Then I don't know what happened. My computer doesn't see my phone anymore, and when I plug it into the computer is doesn't say "usb debugging connected" like it did before. Also when I pull down the notification bar and press menu it doesn't do anything. I thought that was how I mounted my phone before. The only thing that it does is charge the phone when I plug it in to the usb. I have tried on 3 computers, one using windows 7, Vista and XP, and not one of them worked. I seen that other people had this similar problem but I couldn't find an answer. My phone is not rooted either, please help me This is driving me nuts, I need to use my computer at work, and this is the only way I can get internet connection.