I recorded on a DVD-R 8x on LP until there was only 7 minutes left on the disc. However, when I went to finalize the disc, my DVD Recorder told me that it could not record on my disc, and then it was showing that there was still 4 hours left on the disc. Everything that I recorded on the disc is still there, it just won't finalize. Should I keep the disc as it is, or is this a problem that can be solved by a disc doctor?
Try just taking it out of the recorder and putting it back in. The recorder make just have trouble recognizing it. If that doesn't work, try gently cleaning the burning surface of the disc. If that doesn't work, you may need to use ISOBuster to try to recover the disc or you may have to play it unfinalized on your recorder, if you can, and let a VCR record the contents, and then toss the disc. See my sig about media quality. Of course, DVD recorders are nowhere near as reliable as good old tapes, even with good media, so even with good discs you may get the occasional coaster.