DMR-EH55 recording problem

At times when I schedule a program to be recorded, only 10 or 15 seconds of the program records. I have had this happen when doing a manual recording and I enter in all the info(ie. start time, end time, channel) and also if I use the TVGOS GUIDE and select the progam to be recorded. Does anyone know why this problem is occuring???

It may need a firmware update or you may be missing something basic and need to browse the manual: