hey people could someone please tell me why my dvd recorder will not play my home recorded dvd's anymore. It plays commercial ones fine. I been using tdk, jvc, mitsibushi media. It was playing fine but some of the discs are not recognisable but after a few tries become recognisable??? Also im having problems finalizing. It says navigation error after the process is complete? It plays some of my finalized discs but not all. What does this all mean? Why is it reading my commercial dvd's ok but not the ones i made? Do recorders have 2 lenses etc in them? one for reading and one for reading data that the recorder had actually written? Its an LG RH177. It has worked fine for a year, up until last week.