I have a Sandisk 16 GB SDHC card in my Sprint TP - Stock ROM, and just recently I found that after I copied several files to the card using ActiveSync Explore, the files just disappeared. Using Resco Explorer, the files appear in the root of the Storage Card, then within minutes if not seconds, the files just disappear.
Also, when I use Resco Explorer to create a new folder, the folder appears in the list and I can open it to start with, then the folder disappears.
The only action that I did previous to the problem was to attempt to copy the AudioPara3.csv file to the /Windows device folder. There's a several threads on how this file can make the device louder.
Anyway, the device gave a message that stated that the "file already exists in ROM, proceeding with copy could damage system." Since the threads all indicated that the copy was no prblem, I simply tapped "Yes" to proceed.

It seemed to work without a problem, until I copied some files to the Storage Card. They copied fine, then disappeared.
Did a hard Reset, "Clear Storage" that is, and restored from backup. Everything works except files are disappearing!