Hey guys, I just wrote up a topic for another guy here it is:
http://www.samsung-behold.com/samsung-behold-how-to/samsung-cdma-technologies-driver!!!/
You see, this happened to me. Make sure you use your own driver (that worked before) if you can, since the one I attached wasn't the best. The trick is to uninstall the driver through Device Manager, and the computer will think that the phone is first-connected again. Also, you do NOT install the driver before connecting, it messed my setup up before. Also, if you have problems with TK File Explorer not being able to connect, then do this. First unplug the phone, exit TKFE and reopen it. Plug the phone in again and try. That doesn't usually work. This OTHER method, almost always works. With TKFE open and the phone still plugged in, right after you get the connection error, restart the phone (as in, turn it off with the red button, and turn it back on again) WITH the phone still plugged in and TKFE open. Try connecting, and it should work like a charm.