My DVDR04 will play home made discs but will not read Store bought discs. is there a setting that i'm overlooking

Are you closing the disc? If so are you using CRD or CRDW. If you are using CDRW it will not burn in the proper output format. If you use CDR only it should. Also try recording at a slower speed. It has helped me in the past to do so.
A great program to try is CDBurnerXP, and it's free. After you record it then put it back in and run it again, but this time just select "Disc" then from the drop down menu Disc Information [CTRL+I] and read what format you ended up with. Remove that and check a store bought disc and compare.

CDBurnerXP Free CD and DVD burning software

quite possible that the copyright was over ridden and the laser isn't reading the correct format. most dvd's are written in AVI or MPEG or MOV format. a copyright off the main disk has a protection line in it when the dvd is re-recorded that locks out the disk's contents. a regular recorded dvd plays.

IS IT A RECORED ONE, OR STORE BOUGHT, SOME HOME MADE ONES WILL NOT WORK.

If your dvd player on your flat panel tv says "wrong disc" then it usually means that the format used to create the disc is not compatible with your player. Read the manual that came with your tv to figure out what file formats are acceptable for burned discs. Try another disc. Verify with a store bought disc that your player works. If it plays regular discs and not home made or burned media, then you will know that its just the file format used when the disc was created that is causing the issue.

depends on the player 80 quid upwards dvd players have a code setting on the menu look for it to over ride and play all types of dvds.encrypted discs may never play it depends on your players formats.

Assuming your dvd player supports your dvd+r format. You might need to make your dvd player multi-region or remove the region setting all together.

this website have unlock codes for dvd players
http://www.dvdexploder.com/

Those cheap made in china $35 dvd players have no region setting and will play virtually anything.

try to set that in the menu of your remote control , there are several configurations there where you can play your dvd

Try this link. It offers resistor changes which are designed to fix your problem of inability to play any CD R. on that model Nakamichi. jacknz0 http://home.cogeco.ca/~niteowl/Nak_MF51.jpg

have you tried using a laser disc cleaner after alot of use the laser eye can become dusty and make it hard to read

your dvd writer is bad you will have to replace it believe me i now what im talking about i have went through 4 ilo's did the same thing plus 100's of differnt name brand dvd's