Seems to me there've been other threads on this issue with the SIMpad. It may not be an uncommon problem for the device, unfortunately. However, IIRC it may be a problem with the ROM image. As such, it may be curable by a reflash, so I'd suggest keeping your eyes peeled for a serial cable. You might not have to replace any hardware. Which SIMpad model is it, and which CE version does it have on it?