I'm using the USB connection. It used to work fine. It happens with any file on the storage card, large or small. Today I reformatted the storage card in my USB card reader, copied all my data back, and I'm still having the problem. Maybe the card reader in my phone is messed up somehow, but it doesn't make sense that the problem only happens with ActiveSync transfers or SOTI. I can move files back and forth within the phone using Resco all I want without errors.