As a matter of interest, how do you go about copying your recorded content to the PC and then to the DVD-R?
I would recommend using a DVD ripping tool, which lets you export video content by the chapter. From what I recall, DVD Shrink offers this capaibility. When extracting the contents, do not extract the menus, since you will need to create these when authoring your DVD.
Once you have the content exported as VOB files from the DVD recordables, use a DVD authoring program such as Nero Recode, Power Producer, etc. to prepare your content for recording to DVD. These tools also let you create a menu structure for your DVD’s contents, since the original menu structure that your DVD Recorder has added will not be suitable. As the source video is DVD compliant, since it was recorded by your Philips DVD recorder, your DVD authoring should not need to recompress the contents, unless you try fitting more than the DVD’s capacity.
If you get errors, can you mention what is the error message and what task you were carrying out when you got the error? For example, if the you get read errors while extracting the content from the recordable disc, then the DVD-RW is at fault. If however you are getting playback errors when you try to play the disc you have prepared from the PC using the contents of the various DVD-RW’s you have written, then chances are that you are not doing the authoring process properly.