The problem may be the app being moved to the SD card itself. If an app is originally installed to the device and then moved to the card it can create issues. Have you tried uninstalling the app and downloading it directly to the card and installing it there, bypassing the phone. If it will let you do it that way, then this issue shouldn't come up. If not, then you may well have to leave the app on the phone for it to run correctly. At least until you hear back from the app's creators. It is quite unusual to have you need to make those changes. Unless, of course, the phone has been rooted, and then all bets are off.