^^Not 100% correct, sorry.
The confusion is on an extended storage phone like the LTEvo, the physical sd card isn't located at /sdcard, it's located at /sdcard2 as well as its other shortcut, /sdcard/ext_sd.
You can change physical sd cards until the cows come home and not solve the problem.
Use EStrongs File Explorer. Select and copy folders in /sdcard2 (the physical sd card) and paste into /sdcard (a partition of the extended phone storage).
Android always needs a place called /sdcard and just because in the past that was an actual sd card, there's no reason that it has to be. Please see our faq for filesystem details.
By the way, the internal /sdcard partition won't show up using a usb cable.
Try the on-phone method with EStrongs as I suggested.
To get to the internal /sdcard partition on your PC, I use SwiFTP via wifi - things like AirDroid are also effective.
PS - don't copy the LOST.DIR folder between cards or partitions.